How to Cite Scientific Papers: A Guide to Citation Formats

Citing scientific papers correctly is a core skill for students, researchers, and life-science professionals who need to document the sources of their claims, methods, and data. This guide explains the main citation formats used in scientific writing, shows how to build accurate in-text citations and reference lists, and offers practical steps for managing references across a research project. The focus is on the formats most common in the life sciences and related fields, including APA, MLA, Vancouver, and Chicago, with attention to the specific requirements that journals and institutions impose.

Why Citation Format Matters in Scientific Writing

Citation format is not a cosmetic detail. It is the mechanism by which readers locate the exact sources that support a claim, verify the evidence base, and trace the development of an idea. Accurate citations also protect the integrity of the research record. A citation that points to the wrong paper, misrepresents what a source says, or omits a source entirely can mislead readers and undermine trust in the work.

The practical burden of citation formatting is substantial. A study of manuscript resubmission practices found that most research manuscripts are not accepted on first submission and that a major part of the resubmission process is reformatting to another journal's specific requirements, a process separate from revising the scientific content. The same study reported that only 4% of journals offered a fully format-free initial submission and that the effort to comply with submission requirements carries a significant global economic burden, estimated at over $1.1 billion annually when accounting for a research team's time. Authors reported that time spent on reformatting delays most publications by at least two weeks and by over three months in about 20% of manuscripts. Only 11.8% of responding authors expressed satisfaction with the resubmission process, and 91% desired reforming the current system. These findings come from a 2019 analysis published in PLOS ONE, available at PubMed.

The demand for different reference styles is a recognized obstacle. A 2013 commentary in Public Health Action highlighted that the different reference styles demanded by journals, both for in-text citations and manuscript bibliographies, require significant time and attention to minute detail, constituting a tedious obstacle on the road to publication for all authors, especially those from resource-limited countries or those writing in a second language. The authors called for a simpler, standardized format for in-text and bibliography reference citations so that researchers can concentrate on the science and its interpretation instead of fonts and punctuation. The commentary is available at PubMed.

For farmers and animal-production professionals who read or contribute to the scientific literature, understanding citation formats matters for two reasons. First, reading a reference list correctly allows you to locate the original research behind management recommendations, such as vaccination protocols, feed formulations, or biosecurity measures. Second, if you collaborate with researchers, extension specialists, or veterinary advisors on a publication, you will need to follow the citation style that the target journal requires.

Core Principles of Citation

Every citation system serves the same basic function: it connects a specific point in your text to a full description of the source in a reference list. The differences between formats lie in how that connection is made and how the source description is arranged.

In-Text Citations

In-text citations appear at the point where you use a source. They are the bridge between your prose and the reference list. The two main approaches are author-date and numeric.

Author-date systems, such as APA and MLA, place the author's surname and the year of publication in parentheses or in the narrative. For example, an APA in-text citation for a source by the National Center for Biotechnology Information would appear as (National Center for Biotechnology Information, 2024) or as a narrative citation such as "National Center for Biotechnology Information (2024) reported..." The year is essential because the reference list may contain multiple works by the same author, and the date helps the reader identify the correct entry.

Numeric systems, such as Vancouver, assign a number to each source in the order it first appears in the text. The number appears in brackets or superscript, and the reference list is numbered accordingly. This system is common in biomedical journals because it keeps the text clean and allows many citations to be grouped in a single bracket.

Reference List Entries

The reference list entry provides the full bibliographic details needed to locate the source. A typical journal article entry includes the authors, the year of publication, the article title, the journal name, the volume, the issue, and the page range or article identifier. Some formats also require a digital object identifier (DOI) or a URL.

The order of these elements and the punctuation used to separate them vary by format. For example, APA places the year in parentheses after the authors, while MLA places the year near the end of the entry. Vancouver places the year after the journal name. These differences are arbitrary but mandatory for compliance with a given style.

The Role of DOIs and URLs

A digital object identifier (DOI) is a permanent identifier assigned to a scholarly work. It remains stable even if the work moves to a different URL. Most citation formats now require or strongly recommend including a DOI when one is available. If no DOI exists, a stable URL is acceptable in many formats.

For biomedical literature, the National Library of Medicine provides PubMed as a searchable database of citations and abstracts. When you locate a paper in PubMed, the record typically displays the DOI, the journal name, the volume, the issue, and the page range, which are the elements you need to build a correct reference. The National Center for Biotechnology Information provides broader literature resources at NCBI Literature Resources, which can help you verify bibliographic details before you submit a manuscript.

At a Glance: Comparison of Major Citation Formats

The table below compares the most common citation formats used in scientific and academic writing. Use it to identify the format you need and to understand the key differences before you build your reference list.

The choice of format is usually dictated by the target journal or the assignment instructions. When no format is specified, APA is a safe default for most scientific and professional writing because it is widely accepted and well documented.

How to Cite a Scientific Paper in APA Format

APA style is one of the most common formats in the life sciences and social sciences. The 7th edition of the Publication Manual of the American Psychological Association is the current standard. This section explains how to build in-text citations and reference list entries for journal articles, books, and web sources.

Journal Article Reference in APA

The basic structure for a journal article in APA 7th edition is:

Author, A. A., Author, B. B., and Author, C. C. (Year). Title of the article. Journal Name, Volume(Issue), page range. DOI or URL

For example, if you were citing the 2024 study on the uptake of international pressure ulcer guidelines, the reference would follow this structure with the authors listed in the order they appear in the original publication, the year in parentheses, the article title in sentence case, the journal name in italics, and the volume, issue, and page range as shown in the PubMed record. The DOI or URL would be included at the end. The PubMed record for this study is available at PubMed.

In-Text Citation in APA

For a work with one or two authors, cite both names every time. For a work with three or more authors, cite the first author's surname followed by "et al." from the first citation onward. The year always appears in the citation.

A parenthetical citation places the author and year together, for example (Crane et al., 2023). A narrative citation places the author in the sentence and the year in parentheses, for example "Crane et al. (2023) reported that graphical abstracts are used to summarize a scientific paper and promote it on social media." The source for this example is the 2023 editorial on graphical abstracts in Advances in Clinical and Experimental Medicine, available at PubMed.

Web Page Reference in APA

For a web page with an organizational author, the structure is:

Organization Name. (Year, Month Day). Title of the page. Site Name. URL

For example, the National Institute of Standards and Technology maintains a program page for the Research Data Framework. The reference would list NIST as the author, the publication or update date if available, the title of the page, and the URL. The page is available at NIST Research Data Framework. If no date is available, use "(n.d.)" in place of the year.

How to Cite a Scientific Paper in MLA Format

MLA style is common in the humanities but appears in some interdisciplinary scientific writing. The 9th edition of the MLA Handbook is the current standard. MLA uses an author-page in-text citation system and a Works Cited list at the end of the paper.

Journal Article Reference in MLA

The basic structure for a journal article in MLA 9th edition is:

Author, First Name, and Second Author Name. "Title of the Article." Journal Name, vol. Volume, no. Issue, Year, pp. Page range. DOI or URL.

Note that MLA uses "vol." and "no." to label the volume and issue, and the year appears after the issue number instead of after the authors. The page range is preceded by "pp."

In-Text Citation in MLA

MLA in-text citations include the author's surname and the page number where the cited material appears, for example (Smith 45). If the author is named in the sentence, only the page number appears in parentheses. MLA does not require the year in the in-text citation because the Works Cited entry provides the full publication details.

Differences from APA

The most visible differences between MLA and APA are the placement of the year, the use of quotation marks around article titles, and the in-text citation format. MLA places the year near the end of the reference entry, uses quotation marks for article titles, and requires a page number in the in-text citation. APA places the year immediately after the authors, uses no quotation marks for article titles, and does not require a page number for a general citation.

How to Cite a Scientific Paper in Vancouver Format

Vancouver style is the dominant format in biomedical publishing. It uses a numeric citation system, which means sources are numbered in the order they appear in the text. The reference list is numbered to match.

Journal Article Reference in Vancouver

The basic structure for a journal article in Vancouver style is:

Author AA, Author BB, Author CC. Title of the article. Journal Name. Year,Volume(Issue):Pages. DOI or URL.

Note that the authors are listed with the surname first followed by initials, there are no periods after the author initials, and the year appears after the journal name. The volume, issue, and pages are separated by semicolons and colons.

In-Text Citation in Vancouver

In-text citations are numbers in parentheses or square brackets, or superscript numbers. The first source cited becomes number 1, the second becomes number 2, and so on. If you cite the same source again later, you use the same number. When multiple sources support a single claim, you can group the numbers, for example [1,3,5].

Managing Numbered Citations

The challenge with Vancouver style is that renumbering is required if you add or remove a source before submission. This is where reference management software becomes valuable. Tools such as Mendeley, Zotero, and EndNote can automatically renumber citations when you edit your manuscript. A 2025 report on Mendeley-based training for sociology students found that the program improved reference management skills by 40%, increased Mendeley usage by 45%, and improved the ability to correctly format citations and compile bibliographies by 45%. The report is available at Semantic Scholar.

How to Cite a Scientific Paper in Chicago Format

Chicago style offers two systems: author-date and notes and bibliography. The author-date system is more common in the sciences, while the notes and bibliography system is common in history and the humanities.

Chicago Author-Date Reference

The basic structure for a journal article in Chicago author-date style is:

Author, First Name, and Second Author. Year. "Title of the Article." Journal Name Volume, no. Issue: Page range. DOI or URL.

The in-text citation follows the author-date pattern, for example (Smith 2020, 45). The year appears in the reference list after the authors, and the page range appears after the issue number.

Chicago Notes and Bibliography Reference

In the notes and bibliography system, the first citation of a source appears in a footnote with the full bibliographic details. Subsequent citations use a shortened form. The bibliography entry at the end of the paper lists all sources alphabetically.

The footnote format for a journal article is:

First Name Last Name, "Title of the Article," Journal Name Volume, no. Issue (Year): Page range.

The bibliography format is:

Last Name, First Name. "Title of the Article." Journal Name Volume, no. Issue (Year): Page range.

Choosing Between Chicago Systems

Use the author-date system if your target journal specifies it or if your field conventionally uses it. Use the notes and bibliography system if you are writing for a history journal or if your instructor requires footnotes. The notes and bibliography system is more flexible for citing archival materials, interviews, and other non-standard sources.

How to Cite a Scientific Paper Accessed Online

Many scientific papers are accessed through databases such as PubMed, institutional repositories, or journal websites. The citation format for an online source depends on whether the source has a DOI and whether it is the version of record or a preprint.

Citing a Paper with a DOI

When a paper has a DOI, most formats require you to include it. The DOI is a permanent identifier that resolves to the publisher's page for the article. In APA, the DOI is presented as a hyperlink, for example https://doi.org/10.1007/s11192-019-03243-4. In Vancouver, the DOI is included at the end of the reference. The 2019 review of citation count studies in Scientometrics is an example of a paper with a DOI, available at Semantic Scholar.

Citing a Paper without a DOI

If a paper has no DOI, include the URL of the page where you accessed it. For papers found in PubMed, the URL is the PubMed record page. For example, a paper indexed in PubMed can be cited with the PubMed URL, such as PubMed. Some formats prefer the journal's own URL over a database URL, but either is acceptable when no DOI exists.

Citing a Preprint

Preprints are versions of a paper posted to a repository before or during peer review. They are cited differently from published papers because they lack final pagination and may change. In APA, a preprint is cited with the author, year, title, and the repository name and URL. The 2025 paper on SemanticCite is an example of a preprint posted to arXiv, available at Semantic Scholar.

Citing a Dataset or Data Paper

Data papers are a distinct publication format that describes a dataset. A 2026 study in Scientific Data examined the role of data papers in scientific data dissemination and reuse, finding that while data papers significantly enhance dataset visibility and scholarly recognition, most citations emphasize descriptive or contextual information instead of facilitating direct computational, comparative, or synthetic reuse. The study is available at PubMed. When citing a data paper, follow the same format as a journal article. When citing a dataset itself, use the format specified by the repository or the citation style you are following.

How to Cite a Scientific Paper with Multiple Authors

The treatment of multiple authors varies by format and by the number of authors. Some formats require listing every author, while others allow truncation after a certain number.

APA Rules for Multiple Authors

In APA 7th edition, the reference list entry lists up to 20 authors. If there are 21 or more authors, list the first 19, then an ellipsis, then the final author. In the in-text citation, for works with three or more authors, cite the first author's surname followed by "et al." from the first citation onward.

MLA Rules for Multiple Authors

In MLA, the reference list entry lists the first author with the surname first, then the remaining authors in normal order. For works with three or more authors, the in-text citation uses the first author's surname followed by "et al." The Works Cited entry may list all authors or the first author followed by "et al." depending on the number of authors and the preference of your instructor.

Vancouver Rules for Multiple Authors

In Vancouver, the reference list entry lists up to six authors. If there are more than six, list the first six followed by "et al." The in-text citation uses the number assigned to the source, so the number of authors does not affect the in-text format.

Chicago Rules for Multiple Authors

In Chicago author-date, the reference list entry lists up to ten authors. If there are more than ten, list the first seven followed by "et al." The in-text citation uses the first author's surname followed by "et al." for works with four or more authors.

How to Cite a Scientific Paper with No Author

Some sources have no identifiable author, such as organizational reports, standards documents, or web pages published by an institution. In these cases, the organization serves as the author.

APA Treatment of Organizational Authors

In APA, the organization is treated as the author. The in-text citation uses the organization's name and the year, for example (National Institute of Standards and Technology, n.d.). In the reference list, the organization's name appears in the author position. If the organization is also the publisher, the name is repeated in the publisher position.

MLA Treatment of Organizational Authors

In MLA, the organization is treated as the author in the Works Cited entry. The in-text citation uses the organization's name and the page number if available. If the organization has a long name, you may abbreviate it in the in-text citation after introducing the full name.

Vancouver Treatment of Organizational Authors

In Vancouver, the organization is treated as the author. The in-text citation uses the number assigned to the source. The reference list entry places the organization's name in the author position.

Citing a Source with No Author and No Organization

If a source has no author and no organizational author, use the title in place of the author. In APA, the title moves to the author position in the reference list, and the in-text citation uses the title or a shortened version of it. In MLA, the title moves to the author position in the Works Cited entry, and the in-text citation uses the title and page number.

How to Cite a Scientific Paper in a Research Paper

The way you cite sources in a research paper depends on the stage of your work and the requirements of your target journal. This section provides a practical workflow for integrating citations into your writing.

Step 1: Identify the Required Format

Before you write, confirm the citation format required by your target journal, your instructor, or your institution. Check the journal's author guidelines or the assignment instructions. If no format is specified, choose APA as a default for scientific writing.

Step 2: Collect Bibliographic Details as You Read

When you find a source you plan to cite, record the full bibliographic details immediately. Include the authors, year, title, journal, volume, issue, pages, and DOI or URL. The PubMed record for a paper provides all of these details in a consistent layout, which makes it a reliable source for bibliographic information. The National Center for Biotechnology Information provides literature resources at NCBI Literature Resources that can help you verify details.

Step 3: Use Reference Management Software

Reference management software can save substantial time and reduce errors. Tools such as Mendeley, Zotero, and EndNote allow you to store references, organize them by project, and generate citations and bibliographies in multiple formats. A 2025 report on Mendeley-based training found that students who received training showed a 40% improvement in reference management skills and a 45% improvement in their ability to correctly format citations and compile bibliographies. The report is available at Semantic Scholar.

Step 4: Insert Citations as You Write

Insert citations at the point where you use a source. Do not wait until the end of the writing process to add citations, as this increases the risk of missing a source or misplacing a citation. If you are using a numeric format such as Vancouver, the reference management software will assign and renumber citations automatically.

Step 5: Verify Every Citation Before Submission

Before you submit a manuscript, verify that every in-text citation has a corresponding reference list entry and that every reference list entry is cited in the text. Check that the bibliographic details match the original source. Citation verification is an active area of research, with tools being developed to check citation accuracy through full-text analysis. A 2025 paper on SemanticCite describes an AI-powered system that verifies citation accuracy through full-text source analysis and classifies claims as supported, partially supported, unsupported, or uncertain. The paper is available at Semantic Scholar.

Common Citation Mistakes and How to Avoid Them

Even experienced researchers make citation errors. The following are the most common failure patterns and the steps you can take to avoid them.

Mismatched In-Text Citations and Reference List Entries

A citation in the text that has no corresponding reference list entry, or a reference list entry that is never cited in the text, is a common error. This often happens when sources are added or removed during revision. Use the citation-checking feature in your word processor or reference management software to identify mismatches before submission.

Incorrect Author Names or Initials

Author names are a frequent source of errors. Verify the spelling of every author name against the original source or a reliable database such as PubMed. Pay attention to initials, as different formats treat middle initials differently.

Missing or Incorrect DOIs

A DOI that is incomplete, incorrectly formatted, or assigned to the wrong paper is a serious error. Copy the DOI from the publisher's page or the database record instead of typing it manually. Verify that the DOI resolves to the correct article.

Wrong Year of Publication

The year of publication is essential in author-date formats. For online-first articles, the year of the version of record may differ from the year of the online-first release. Use the year that appears in the final published version unless your target journal specifies otherwise.

Inconsistent Formatting

Mixing elements of different citation formats in a single reference list is a common error. For example, using APA in-text citations with Vancouver reference list entries. Choose one format and apply it consistently throughout the manuscript.

Citing a Source You Have Not Read

Citing a source that you have not read, often by copying a citation from another paper, is a serious ethical and accuracy problem. The 2019 review of citation count studies noted that a paper may be cited for very different scientific and non-scientific reasons, and that citation context, semantics, linguistic patterns, location within the citing document, and citation polarity should all be analyzed to understand the relationship between citing and cited documents. The review is available at Semantic Scholar. Always read the source before citing it, and cite it for the specific claim it supports.

Tools and Resources for Managing Citations

Several tools and resources can help you manage citations and format references correctly.

Reference Management Software

Mendeley, Zotero, and EndNote are the most widely used reference management tools. They allow you to import references from databases such as PubMed, organize them into folders, and generate citations and bibliographies in hundreds of formats. The 2025 Mendeley training report demonstrated that structured training in reference management software can substantially improve citation formatting skills. The report is available at Semantic Scholar.

Citation Databases

PubMed is the primary database for biomedical literature and provides reliable bibliographic records for millions of papers. The National Library of Medicine maintains PubMed, and the National Center for Biotechnology Information provides broader literature resources at NCBI Literature Resources. These databases are useful for verifying author names, journal names, volume and issue numbers, page ranges, and DOIs.

Reporting Guidelines and Standards

For research in health and related fields, reporting guidelines provide standards for what to include in a manuscript. The EQUATOR Network is an international initiative that provides a comprehensive collection of reporting guidelines for health research. The network's resources are available at EQUATOR Network. Following the relevant reporting guideline for your study type can improve the completeness and transparency of your manuscript, including the accuracy of your citations.

Research Data Frameworks

For research that involves data management, the National Institute of Standards and Technology maintains the Research Data Framework, which provides a structure for describing and managing research data. The framework is described at NIST Research Data Framework. Proper data management supports accurate citation of datasets and data papers.

Experimental Design Support

For animal research and other experimental studies, the NC3Rs Experimental Design Assistant provides guidance on experimental design and reporting. The tool is available at NC3Rs Experimental Design Assistant. Good experimental design and reporting reduce the risk of errors that could affect the validity of your citations and your conclusions.

Citation Formats for Special Source Types

Scientific writing draws on many source types beyond journal articles. This section covers the formats for books, book chapters, conference papers, reports, and software.

Books

In APA, a book reference is:

Author, A. A. (Year). Title of the book (Edition ed.). Publisher. DOI or URL.

In MLA, a book reference is:

Author, First Name. Title of the Book. Edition ed., Publisher, Year.

In Vancouver, a book reference is:

Author AA. Title of the book. Edition ed. Place of publication: Publisher, Year.

Book Chapters

In APA, a book chapter reference is:

Author, A. A. (Year). Title of the chapter. In E. E. Editor (Ed.), Title of the book (pp. page range). Publisher. DOI or URL.

In MLA, a book chapter reference is:

Author, First Name. "Title of the Chapter." Title of the Book, edited by Editor Name, Publisher, Year, pp. page range.

Conference Papers

Conference papers are cited similarly to journal articles but include the conference name and location. In APA, a conference paper reference is:

Author, A. A. (Year, Month). Title of the paper [Paper presentation]. Conference Name, Location. URL.

Reports

Reports from government agencies, research organizations, and international bodies are cited with the organization as the author. In APA, a report reference is:

Organization Name. (Year). Title of the report (Report Number). Publisher. URL.

Software and Data

Software citations are becoming more common as research becomes more computational. A 2024 study in Scientometrics examined how official software citation formats evolve over time through a longitudinal analysis of R programming language packages. The study is available at Semantic Scholar. When citing software, include the software name, version, creator, and the URL or repository where it can be accessed.

How to Cite a Scientific Paper in a Literature Review

Literature reviews synthesize findings from multiple studies, which means they rely heavily on citations. The way you cite sources in a literature review depends on the type of review and the target journal.

Narrative Reviews

Narrative reviews summarize and interpret the literature on a topic. They typically use author-date or numeric citations, depending on the journal. A 2026 study on utilizing artificial intelligence to create narrative literature reviews explored how AI tools can aid in identifying research gaps, organizing and analyzing retrieved articles, and writing the review. The study is available at Europe PMC. Regardless of whether you use AI tools, the citation requirements for a narrative review are the same as for any other manuscript.

Systematic Reviews

Systematic reviews follow a structured methodology and report their search and screening processes in detail. The PRISMA guidelines, available through the EQUATOR Network, provide a standard for reporting systematic reviews. A 2024 study on question answering for electronic health records described a systematic screening process that followed PRISMA guidelines, identifying 4111 papers and screening them to obtain 47 papers for final review. The study is available at PubMed. Systematic reviews require complete and accurate citations for all included studies, as the reference list is a key part of the evidence base.

Citation Analysis in Reviews

Some reviews analyze citation patterns themselves. A 2024 study in International Wound Journal analyzed the citations of the International Clinical Practice Guidelines for preventing and treating pressure ulcers and injuries, finding that the three guideline editions were cited more than 2800 times in the scientific literature from 2009 to 2023, exceeding the thresholds of highly cited papers in clinical medicine. The study is available at PubMed. This type of analysis requires careful attention to citation formats, as the researchers had to identify and categorize thousands of citations.

Citation and Research Integrity

Accurate citation is a matter of research integrity. Citing sources correctly gives credit to the original authors, allows readers to verify your claims, and situates your work within the broader literature.

The Problem of Citation Errors

Citation errors can misrepresent the source literature. A 2025 paper on SemanticCite noted that academic literature faces mounting challenges, including semantic citation errors that misrepresent sources, AI-generated hallucinated references, and traditional citation formats that point to entire papers without indicating which sections substantiate specific claims. The paper is available at Semantic Scholar. These problems can be addressed through careful verification of every citation before submission.

Copyright and Citation

Copyright conditions can affect the use of assessment tools and other materials in research. A 2026 study in PLOS ONE examined the benefits and harms of copyright restrictions on burnout and other psychometric assessment scales, comparing the citation trends of restrictive surveys against free-to-use surveys. The study found that the restrictive surveys initially showed rising citation ratios but declined in later years, while the permissive surveys showed positive final slope segments. The study is available at Europe PMC. When you cite a source, you are referencing it, not reproducing it. Reproducing substantial portions of a copyrighted work requires permission, regardless of the citation format.

Citation and Scientific Impact

Citation counts are often used as a measure of scientific impact, but they are an imperfect measure. A 2019 review in Scientometrics examined what citation counts measure, covering 41 studies published between 2006 and 2018. The review found that a paper may be cited for very different scientific and non-scientific reasons, and that to understand the relationship between citing and cited documents, researchers should analyze the citation context, the semantics and linguistic patterns in citations, citation locations within the citing document, and citation polarity. The review is available at Semantic Scholar. When you cite a source, you contribute to its citation count, so it is important to cite accurately and for the right reasons.

Frequently Asked Questions

What is the difference between APA and MLA citation formats?

APA and MLA differ in the placement of the year, the in-text citation format, and the structure of the reference list. APA uses an author-date in-text citation, places the year in parentheses after the authors in the reference list, and does not use quotation marks around article titles. MLA uses an author-page in-text citation, places the year near the end of the reference entry, and uses quotation marks around article titles. APA is common in the social sciences and life sciences, while MLA is common in the humanities.

How do I cite a scientific paper with no page numbers?

If a scientific paper has no page numbers, as is the case with many online-first articles, use the article identifier or DOI in place of the page range. In APA, you can cite the article with the DOI and note the article number if one is provided. In MLA, you can cite the article without a page number if none is available. In Vancouver, the article identifier is used in place of the page range.

What is a DOI and why is it important for citations?

A DOI, or digital object identifier, is a permanent identifier assigned to a scholarly work. It remains stable even if the work moves to a different URL. Most citation formats require or strongly recommend including a DOI when one is available because it provides a reliable link to the source. You can find the DOI on the publisher's page for the article or in the database record, such as the PubMed record.

How many authors should I list in a citation?

The number of authors to list depends on the citation format. APA 7th edition lists up to 20 authors in the reference list. MLA lists all authors in the Works Cited entry. Vancouver lists up to six authors, then uses "et al." for additional authors. Chicago author-date lists up to ten authors. For in-text citations, most formats use the first author's surname followed by "et al." for works with three or more authors.

Can I use a citation generator to format my references?

Citation generators can be helpful, but they are not always accurate. Always verify the output against the original source or a reliable database such as PubMed. Reference management software such as Mendeley, Zotero, and EndNote is more reliable than web-based citation generators because it stores the bibliographic details and formats them consistently. A 2025 study found that structured training in Mendeley improved citation formatting skills by 45%. The study is available at Semantic Scholar.

How do I cite a source that I found cited in another paper?

If you find a source cited in another paper, you should locate and read the original source before citing it. Citing a source that you have not read, often by copying a citation from another paper, is a serious accuracy and integrity problem. If you cannot access the original source, cite the source you did read and note that it is cited in that source. This is called a secondary citation, and the format varies by citation style.

What is the difference between a reference list and a bibliography?

A reference list includes only the sources that you cited in your text. A bibliography includes all the sources you consulted, whether or not you cited them. APA and Vancouver use reference lists. MLA uses a Works Cited list, which includes only the sources cited in the text. Chicago notes and bibliography uses a bibliography, which may include sources consulted but not cited.

How do I cite a preprint or a paper that is not yet published?

Preprints are cited with the author, year, title, and the repository name and URL. The format varies by citation style, but the key elements are the same. For example, the SemanticCite preprint is available at Semantic Scholar. When citing a preprint, note that it has not been peer reviewed and may change before final publication.

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References and Further Reading

• Research Data Framework. National Institute of Standards and Technology.
• EQUATOR Network. EQUATOR Network.
• Experimental Design Assistant. NC3Rs.
• NCBI Literature Resources. National Center for Biotechnology Information.
• PubMed. National Library of Medicine.
• The uptake of the international pressure ulcer/injury prevention and treatment guidelines: An updated systematic citation analysis.. International wound journal, 2024.
• In a blink of an eye: Graphical abstracts in Advances in Clinical and Experimental Medicine.. Advances in clinical and experimental medicine : official organ Wroclaw Medical University, 2023.
• The high resource impact of reformatting requirements for scientific papers.. PloS one, 2019.
• Folic acid supplementation and malaria susceptibility and severity among people taking antifolate antimalarial drugs in endemic areas.. The Cochrane database of systematic reviews, 2022.
• References for scientific papers: why not standardise to one global style?. Public health action, 2013.
• Question Answering for Electronic Health Records: Scoping Review of Datasets and Models.. Journal of medical Internet research, 2024.
• Changing Trends in Conscious Sedation at Pediatric Dental Offices: A Bibliometric Analysis.. Cureus, 2023.
• The Role of Data Papers in Scientific Data Dissemination and Reuse.. Scientific data, 2026.
• Correction: The spiritual core of the hard problem: consciousness as foundational, not emergent.. 2026.
• Utilizing Artificial Intelligence to create narrative literature reviews.. 2026.
• On the makeup of high-impact reviews in ecology.. 2026.
• Benefits and harms of copyright restrictions and conditions on burnout and other psychometric assessment scales.. 2026.
• Iran's great scientific divergence: The Middle-Income trap and the Political Economy of Science Policy.. 2026.
• Editorial: Mining Scientific Papers, Volume II: Knowledge Discovery and Data Exploitation. Frontiers in Research Metrics and Analytics, 2022.
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