Citation Styles in Research: APA vs. AMA vs. Vancouver (and How to Choose)

A citation style is a standardized set of rules for how sources are cited in the text of a manuscript and listed in its reference list. Different disciplines and journals rely on different citation styles, and three of the most common in scientific and academic publishing are APA, AMA, and Vancouver. Which style a manuscript must follow is almost always decided by the journal, not the author, which makes it important to understand how these styles differ before a single reference is formatted.

This article covers the following:

• What a citation style is and why journals require a specific one
• How APA, AMA, and Vancouver work, presented as citation styles with examples of each pattern
• A side-by-side comparison of the three citation styles
• How to choose the right style for a manuscript, and why journal-specific variations matter
• Common mistakes that cause reference problems at submission

What Is a Citation Style?

Every citation style has two components: the in-text citation, which points the reader to a source at the exact place it is used, and the reference list, which gives the full details of each source at the end of the paper. The many types of referencing styles used in research, including the scientific citation styles covered below, fall into two broad systems, and reference styles in research journals follow one or the other. In an author-date system, the in-text citation names the author and year, and the reference list is arranged alphabetically. In a numbered system, each source is assigned a number, and the reference list is arranged in the order the sources first appear in the text.

Journals specify a style for consistency. A uniform format helps readers locate the sources behind a claim, and it helps editors and production teams process manuscripts efficiently. The instructions for authors of each journal state which style to use, and those instructions always take precedence over any general convention.

APA Style

APA style is published by the American Psychological Association and is widely used in psychology, education, and other social and behavioral sciences. It is an author-date system. In-text citations give the author’s surname and the year of publication, for example (Smith, 2020). In the seventh edition of the APA manual, sources with three or more authors are cited with the first author’s surname followed by “et al.” from the first mention. The reference list is arranged alphabetically by the first author’s surname.

A journal article reference in APA style follows this pattern, with the journal title and volume number in italics:

Author, A. A., & Author, B. B. (Year). Title of the article in sentence case. Journal Name, volume(issue), page range. https://doi.org/xxxxx

AMA Style

AMA style, also called the AMA citation style or AMA format, is published by the American Medical Association in the AMA Manual of Style, now in its 11th edition, and is widely used in medicine and the health sciences. It is a numbered system. AMA style in-text citations are superscript numerals assigned in the order sources first appear, and the reference list follows the same numerical order. Journal names are abbreviated and italicized. AMA style lists up to six authors; when a source has more than six, the first three are listed, followed by “et al.”

A journal article reference in AMA style follows this pattern:

1. Author AA, Author BB. Title of the article. Abbreviated Journal Name. Year;volume(issue):page range. doi:xxxxx

Vancouver Style

Vancouver style is a numbered system used widely in biomedical and life sciences journals. It takes its name from a meeting of medical journal editors in Vancouver in the late 1970s, which led to the group now known as the International Committee of Medical Journal Editors (ICMJE), and its reference formats are based on the National Library of Medicine’s guidance for citing medical literature. Vancouver style in-text citations are numerals, which may appear in square brackets, in parentheses, or as superscripts depending on the journal, and the reference list follows the order of first citation.

A journal article reference in Vancouver style generally follows this pattern:

1. Author AA, Author BB. Title of the article. Abbreviated Journal Name. Year;volume(issue):page range.

Vancouver style is less a single fixed standard than a family of closely related formats. Many journals adopt it with their own adjustments to punctuation, in-text numbering, or the number of authors listed before “et al.” AMA and Vancouver are closely related numbered styles, and their differences lie mainly in such details. For how “et al.” is handled across APA, Vancouver, and AMA, the article How Do You Use et al. in Scientific Papers? offers many examples.

APA vs. AMA vs. Vancouver at a Glance

<table style="width:100%; border-collapse:collapse;">
  <thead>
    <tr>
      <th style="border:1px solid #ddd; padding:10px; text-align:left;">Feature</th>
      <th style="border:1px solid #ddd; padding:10px; text-align:left;">APA</th>
      <th style="border:1px solid #ddd; padding:10px; text-align:left;">AMA</th>
      <th style="border:1px solid #ddd; padding:10px; text-align:left;">Vancouver</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td style="border:1px solid #ddd; padding:10px;"><strong>System</strong></td>
      <td style="border:1px solid #ddd; padding:10px;">Author-date</td>
      <td style="border:1px solid #ddd; padding:10px;">Numbered</td>
      <td style="border:1px solid #ddd; padding:10px;">Numbered</td>
    </tr>
    <tr>
      <td style="border:1px solid #ddd; padding:10px;"><strong>Published by</strong></td>
      <td style="border:1px solid #ddd; padding:10px;">American Psychological Association</td>
      <td style="border:1px solid #ddd; padding:10px;">American Medical Association</td>
      <td style="border:1px solid #ddd; padding:10px;">Based on ICMJE recommendations and National Library of Medicine formats</td>
    </tr>
    <tr>
      <td style="border:1px solid #ddd; padding:10px;"><strong>In-text citation</strong></td>
      <td style="border:1px solid #ddd; padding:10px;">(Author, Year)</td>
      <td style="border:1px solid #ddd; padding:10px;">Superscript numerals in order of appearance</td>
      <td style="border:1px solid #ddd; padding:10px;">Numerals in brackets, parentheses, or superscript, depending on the journal</td>
    </tr>
    <tr>
      <td style="border:1px solid #ddd; padding:10px;"><strong>Reference list order</strong></td>
      <td style="border:1px solid #ddd; padding:10px;">Alphabetical by first author</td>
      <td style="border:1px solid #ddd; padding:10px;">Order of first citation</td>
      <td style="border:1px solid #ddd; padding:10px;">Order of first citation</td>
    </tr>
    <tr>
      <td style="border:1px solid #ddd; padding:10px;"><strong>Authors in the list</strong></td>
      <td style="border:1px solid #ddd; padding:10px;">Names listed in full (up to 20 authors in the 7th edition)</td>
      <td style="border:1px solid #ddd; padding:10px;">Up to six authors, then first three plus “et al.”</td>
      <td style="border:1px solid #ddd; padding:10px;">Varies by journal</td>
    </tr>
    <tr>
      <td style="border:1px solid #ddd; padding:10px;"><strong>Journal names</strong></td>
      <td style="border:1px solid #ddd; padding:10px;">Written in full</td>
      <td style="border:1px solid #ddd; padding:10px;">Abbreviated</td>
      <td style="border:1px solid #ddd; padding:10px;">Abbreviated</td>
    </tr>
    <tr>
      <td style="border:1px solid #ddd; padding:10px;"><strong>Typical fields</strong></td>
      <td style="border:1px solid #ddd; padding:10px;">Psychology, education, social and behavioral sciences</td>
      <td style="border:1px solid #ddd; padding:10px;">Medicine and health sciences</td>
      <td style="border:1px solid #ddd; padding:10px;">Biomedical and life sciences</td>
    </tr>
  </tbody>
</table>

Other styles are common in other fields. Chicago style is often used in business, history, and the arts, MLA style in the humanities, and IEEE style, another numbered system, in engineering and computer science. Harvard referencing is a general author-date approach whose details differ between institutions.

How to Choose a Citation Style

Start with the target journal’s instructions for authors. The journal’s guidelines name the required style and often specify details such as how many authors to list and how to format DOIs. If the guidelines name a style, no other choice is available.

Follow the field’s convention when no style is specified. For a thesis or an unpublished paper, the department or institution usually sets the style. Where none is set, the dominant convention in the discipline is the safest choice, such as APA in psychology or AMA in medicine.

Use a reference manager with the right style file. Tools such as Zotero, Mendeley, and EndNote store references once and format them in thousands of styles, which makes switching styles far easier. The output still needs checking, since auto-formatting can introduce errors. The article Questionable Research Practices also touches on reference managers.

Check for journal-specific variations. A journal that uses “Vancouver style” may still require its own punctuation, in-text numbering, or author limits. The guidelines should be read for these details, not assumed from the style’s name.

Verify the match between citations and references. Every in-text citation should appear in the reference list, and every reference should be cited in the text. In numbered styles, the numbering order must be correct. Ask an Expert: Manuscript Formatting lists mismatches and the wrong referencing style among common formatting problems.

Reformatting an entire reference list for a new journal is one of the more tedious steps of resubmission, and some researchers choose to hand it to a specialist. AJE’s manuscript formatting service prepares a manuscript, including its references, to match the target journal’s guidelines.

Common Mistakes to Avoid

• Using the wrong style for the target journal, such as numbered references when the journal requires author-date
• Leaving mismatches between in-text citations and the reference list, including references that are never cited and citations missing from the list
• Mixing styles within one manuscript, such as author-date citations in the text with a numbered reference list
• Assuming “Vancouver style” or “AMA style” is identical across journals and skipping the journal’s own variations
• Ignoring the style’s rules for “et al.” and author lists, including using “et al.” in a reference list where the journal requires authors to be named
• Trusting reference manager output without checking it against the journal’s guidelines
• Leaving reference formatting to the last minute before submission

Final Thoughts

APA, AMA, and Vancouver are not competing standards so much as conventions that belong to different fields and journals. The practical task for a researcher is rarely to pick a favorite. It is to identify the style the target journal requires, learn its patterns, and apply them consistently from the first draft. Researchers who want an expert to review the language of a manuscript alongside its preparation for submission can also use AJE’s editing services, which are designed to help a manuscript meet the standards journals expect.