How to Cite Multiple Authors in Every Major Style

One of the most common citation questions is deceptively simple: how many authors do you list? The answer depends on your citation style, whether it's an in-text citation or a reference list entry, and how many authors the source actually has. Get it wrong and you'll lose points on formatting -- or worse, obscure who actually conducted the research.

This guide covers the rules for every major citation style, from single-author works to those massive 30-author scientific papers.

Quick Reference Table

Here's the full picture at a glance. The sections below explain each style in detail with examples.

APA 7th Edition

APA 7th made a major change from the 6th edition: it now allows up to 20 authors in the reference list before using an ellipsis. This was a direct response to the growth of large collaborative research in STEM.

In-Text Citations

One author:

(Smith, 2024)

Smith (2024) found that...

Two authors: Always list both, connected with "&" in parenthetical or "and" in narrative:

(Smith & Jones, 2024)

Smith and Jones (2024) found that...

Three or more authors: Use the first author followed by "et al." from the very first citation:

(Smith et al., 2024)

Smith et al. (2024) found that...

This is different from APA 6th, which required listing all authors (up to five) on first mention. APA 7th simplified this -- it's always "et al." for three or more, every time.

Reference List

One to twenty authors: List all of them. Use commas between authors, an ampersand before the last author, and initials only for given names:

Smith, J. D., Jones, M. K., Brown, R. L., Davis, P. A., Wilson, T. R., Taylor, S. M., & Anderson, K. J. (2024). Article title in sentence case. Journal Name, 15(3), 45--62. https://doi.org/10.1234/example

Twenty-one or more authors: List the first 19, then an ellipsis (...), then the last author. No ampersand before the ellipsis:

Smith, J. D., Jones, M. K., Brown, R. L., Davis, P. A., Wilson, T. R., Taylor, S. M., Anderson, K. J., Thomas, B. C., Jackson, L. E., White, H. F., Harris, D. G., Martin, R. J., Thompson, C. A., Garcia, M. L., Martinez, J. P., Robinson, A. W., Clark, N. S., Rodriguez, E. T., Lewis, F. K., ... Zhang, Y. Q. (2024). Article title. Journal Name, 15(3), 45--62.

This 20-author rule is one of the most notable changes in APA 7th. Previously, APA 6th capped at 7 authors before the ellipsis. If you're working from older templates or guides, double-check this. For a full rundown of APA basics, see our APA citation guide.

MLA 9th Edition

MLA takes a simpler approach to multiple authors than most styles.

In-Text Citations

One author:

(Smith 42)

Two authors: List both, connected with "and":

(Smith and Jones 42)

Three or more authors: First author followed by "et al.":

(Smith et al. 42)

Works Cited

One author:

Smith, John D. "Article Title." Journal Name, vol. 15, no. 3, 2024, pp. 45--62.

Two authors: First author inverted, second author in normal order:

Smith, John D., and Mary K. Jones. "Article Title." Journal Name, vol. 15, no. 3, 2024, pp. 45--62.

Three or more authors: First author followed by "et al.":

Smith, John D., et al. "Article Title." Journal Name, vol. 15, no. 3, 2024, pp. 45--62.

MLA gives you the option to list all authors instead of using "et al." for three or more, but "et al." is the standard and what most instructors expect.

Chicago 17th Edition

Chicago's rules depend on whether you're using the notes-bibliography (NB) or author-date (AD) system.

Notes-Bibliography: Footnotes

One author:

1. John D. Smith, "Article Title," Journal Name 15, no. 3 (2024): 45.

Two authors:

1. John D. Smith and Mary K. Jones, "Article Title," Journal Name 15, no. 3 (2024): 45.

Three authors: List all three:

1. John D. Smith, Mary K. Jones, and Robert L. Brown, "Article Title," Journal Name 15, no. 3 (2024): 45.

Four or more authors: First author followed by "et al.":

1. John D. Smith et al., "Article Title," Journal Name 15, no. 3 (2024): 45.

Notes-Bibliography: Bibliography

In the bibliography, list up to 10 authors. For 11 or more, list the first 7 followed by "et al." The first author's name is inverted:

Smith, John D., Mary K. Jones, and Robert L. Brown. "Article Title." Journal Name 15, no. 3 (2024): 45--62.

Author-Date

The author-date system follows similar rules to APA for in-text citations. In the reference list, Chicago author-date lists up to 10 authors before truncating.

For a broader comparison of how Chicago differs from other styles, see our APA vs MLA vs Chicago guide.

Harvard Style

Harvard varies between institutions, but the most common convention follows these rules:

In-Text Citations

One author:

(Smith, 2024)

Two authors: Connected with "and":

(Smith and Jones, 2024)

Three authors: List all three on first mention, then use "et al." subsequently:

First: (Smith, Jones and Brown, 2024) Subsequent: (Smith et al., 2024)

Four or more authors: Use "et al." from the first mention:

(Smith et al., 2024)

Reference List

List all authors regardless of how many there are. Some Harvard guides cap at 6 or 7 before using "et al." -- check your institution's specific guidelines. The general format:

Smith, J.D., Jones, M.K. and Brown, R.L. (2024) 'Article title', Journal Name, 15(3), pp. 45--62.

Note that Harvard uses "and" (not "&") between the last two authors. For complete Harvard formatting, see our Harvard referencing guide.

IEEE

IEEE uses a numbered reference system, so in-text citations are just numbers in brackets. The author formatting only matters in the reference list.

In-Text

All citations are numbered:

Studies have shown improved results 1, 3, 7.

The number of authors doesn't change the in-text format.

Reference List

One author:

1 J. D. Smith, "Article title," Journal Name, vol. 15, no. 3, pp. 45--62, 2024, doi: 10.1234/example.

Two authors:

1 J. D. Smith and M. K. Jones, "Article title," Journal Name, vol. 15, no. 3, pp. 45--62, 2024.

Three or more authors: IEEE lists the first author followed by "et al." for works with more than six authors. For six or fewer, list all of them:

1 J. D. Smith, M. K. Jones, R. L. Brown, P. A. Davis, T. R. Wilson, S. M. Taylor, and K. J. Anderson, "Article title," Journal Name, vol. 15, no. 3, pp. 45--62, 2024.

2 J. D. Smith et al., "Article title," Journal Name, vol. 15, no. 3, pp. 45--62, 2024.

For more on IEEE formatting, see our IEEE citation style guide.

Vancouver

Vancouver is another numbered system, commonly used in biomedical journals.

In-Text

Like IEEE, in-text citations are numbers:

Studies have demonstrated improved outcomes (1, 3, 7).

Or with superscript numbers depending on the journal.

Reference List

One to six authors: List all of them. Names are abbreviated (last name, initials, no periods):

1. Smith JD, Jones MK, Brown RL, Davis PA, Wilson TR, Taylor SM. Article title. Journal Name. 2024;15(3):45-62.

Seven or more authors: List the first six, then "et al.":

1. Smith JD, Jones MK, Brown RL, Davis PA, Wilson TR, Taylor SM, et al. Article title. Journal Name. 2024;15(3):45-62.

See our Vancouver citation style guide for the complete formatting rules.

Understanding "Et Al."

"Et al." is short for et alii, Latin for "and others." A few rules apply across all styles:

• Always include the period after "al." -- it's an abbreviation. There's no period after "et" because "et" is a complete word.
• It isn't italicized in most styles (APA, MLA, Chicago). Some older guides italicize it, but current editions don't.
• Never use "et al." for two authors. Every style requires both names when there are exactly two.
• The threshold for using "et al." varies by style. APA and MLA use it for three or more. Chicago NB uses it for four or more. IEEE and Vancouver use it for seven or more in the reference list.

Common Mistakes

1. Using "et al." for two-author works. No style allows this. Two authors are always both listed.
2. Mixing up "&" and "and." APA uses "&" in parenthetical citations and reference lists, but "and" in narrative citations. MLA, Chicago, and Harvard use "and" everywhere. Don't mix conventions from different styles.
3. Applying APA 6th rules to APA 7th. The 6th edition listed up to 5 authors on first in-text mention. The 7th edition uses "et al." for 3+ authors from the first citation. The 6th edition truncated at 7 authors in the reference list. The 7th edition allows up to 20. If you're using an older template, update it.
4. Forgetting to invert the first author's name. In reference lists, the first author is typically listed last name first (Smith, J. D.). Subsequent authors may be in normal order depending on the style.
5. Omitting authors entirely. For sources with no identifiable author, use the organization name (for institutional works) or the title (for anonymous works). Don't leave the author field blank.
6. Inconsistent formatting within a paper. If you use "et al." for one 4-author source, use it for all 4-author sources. Inconsistency signals carelessness.

Try It with CiteTools

Counting authors and remembering truncation rules for each style is exactly the kind of tedious work that should be automated. Paste any DOI, URL, ISBN, or messy reference into CiteTools.io and the author formatting is handled automatically -- correct number listed, correct order, correct punctuation, correct "et al." threshold for your chosen style. Switch between all six styles with one click.