Four Common Citation Errors in APA

• Kathryn Vela
• Published on 11/05/2025

1. Secondary Citations

A “secondary source” refers to content that was previously reported in another source, known as the “primary source.”

The best practice is to cite the primary source whenever possible and use secondary sources only as needed. Even so, secondary sources still need to be cited just like any other source.

A common error that researchers will make when citing a secondary source is failing to include information about the primary source.  

 For example, let’s say you read an article by Smith et al. (2023) that referred to an article written by Roberts et al. (2005). You aren’t able to find the original Roberts article, so you have to cite the secondary source Smith article. The in-text citation would look like this:

Example	(Roberts et al., 2005, as cited in Smith et al., 2023)
Structure	(Authors, Year, as cited in Authors, Year)

 2. Multiple Authors

Citing multiple authors can get tricky in APA, especially when you’re dealing with works that have a lot of authors listed.

 There are three structures to citing multiple authors in APA, and which one you use depends on how many authors are listed in the work. You will never have to list more than twenty authors in a citation. 

Luckily, APA style clearly describes how to handle multiple authors in a citation, and these rules apply to all types of works.

Two Authors

List the authors by their surnames and initials, separate them with a comma, and use an ampersand in between the two names.

Citation	Varady, K. A., & Jones, P. J. (2005). Combination diet and exercise interventions for the treatment of dyslipidemia: an effective preliminary strategy to lower cholesterol levels?. The Journal of Nutrition, 135(8), 1829–1835. https://doi.org/10.1093/jn/135.8.1829
Structure	Surname, Initial., & Surname, Initial. (Year). Title of article. Full Journal Title, Volume(Issue), start page-end page. DOI or URL

Three to Twenty Authors

This citation will look just like the two-author format above; list each author by surname and initials separated by a comma, and before the last author, insert an ampersand.

Citation	Kite, C., Lahart, I. M., Afzal, I., Broom, D. R., Randeva, H., Kyrou, I., & Brown, J. E. (2019). Exercise, or exercise and diet for the management of polycystic ovary syndrome: a systematic review and meta-analysis. Systematic Reviews, 8(1), 51. https://doi.org/10.1186/s13643-019-0962-3
Structure	Surname, Initial., Surname, Initial., Surname, Initial., Surname, Initial., & Surname, Initial. (Year). Title of article. Full Journal Title, Volume(Issue), start page-end page. DOI or URL

More than Twenty Authors

List the first 19 authors using the same format as above, listing the surname and initials separated by a comma. After the nineteenth author’s name, insert an ellipsis, then add the final author’s surname and initials.

Citation

Pearson, G. J., Thanassoulis, G., Anderson, T. J., Barry, A. R., Couture, P., Dayan, N., Francis, G. A., Genest, J., Grégoire, J., Grover, S. A., Gupta, M., Hegele, R. A., Lau, D., Leiter, L. A., Leung, A. A., Lonn, E., Mancini, G. B. J., Manjoo, P., McPherson, R., Ngui, D., … Wray, W. (2021). 2021 Canadian Cardiovascular Society Guidelines for the Management of Dyslipidemia for the Prevention of Cardiovascular Disease in Adults. The Canadian Journal of Cardiology, 37(8), 1129–1150. https://doi.org/10.1016/j.cjca.2021.03.016

Structure

Surname, Initial., Surname, Initial., Surname, Initial., Surname, Initial., Surname, Initial., Surname, Initial., Surname, Initial., Surname, Initial., Surname, Initial., Surname, Initial., Surname, Initial., Surname, Initial., Surname, Initial., Surname, Initial., Surname, Initial., Surname, Initial., Surname, Initial., Surname, Initial., Surname, Initial., … Surname, Initial. (Year). Title of article. Full Journal Title, Volume(Issue), start page-end page. DOI or URL

3. Digital Object Identifiers

Digital Object Identifiers, or DOIs, are unique and persistent identifiers assigned to digital objects, such as articles, books, reports, and datasets. They ensure that researchers can consistently access digital works over time.

 When creating a citation, people might confuse the URL for the work with the DOI. It’s essential to distinguish between them because URLs can break, but DOIs are permanent.

If a work provides a DOI, it should be included in the reference list citation. If a work doesn’t include a DOI, then you can cite the source’s URL.

Citation	Kite, C., Lahart, I. M., Afzal, I., Broom, D. R., Randeva, H., Kyrou, I., & Brown, J. E. (2019). Exercise, or exercise and diet for the management of polycystic ovary syndrome: a systematic review and meta-analysis. Systematic Reviews, 8(1), 51. https://doi.org/10.1186/s13643-019-0962-3
Structure	Surname, Initial., Surname, Initial., Surname, Initial., Surname, Initial., & Surname, Initial. (Year). Title of article. Full Journal Title, Volume(Issue), start page-end page. https://doi.org/10.0000/0000

If no DOI has been provided, then you can list the URL, which would look like this:

Citation

Surname, Initial., Surname, Initial., Surname, Initial., Surname, Initial., & Surname, Initial. (Year). Title of article. Full Journal Title, Volume(Issue), start page-end page. https://www.someaddress.com/url

4. Versioning

Sometimes, a source will have multiple editions or versions with the same authors and title, but published in different years. This is most often seen in books, but can also occur in journal articles, datasets, and other types of sources.

 If you fail to specify which edition of a work you are referencing, you could confuse your readers. And in APA, if a work is not the first edition, you are required to list the specific edition in the citation.

Here’s how that would look for a book citation:

Citation	Madigan, S. (2026). Narrative therapy (3rd ed.). American Psychological Association. https://doi.org/10.1037/0000479-000
Structure	Surname, Initial. (Year). Title of work: Subtitle (# ed.). Publisher. https://doi.org/10.0000/0000

Double-check the author name punctuation – make sure a comma separates the surname and initials, and that double initials are separated by a period. Refer to the primary source whenever possible – only cite the secondary source if you can’t locate the primary source. Include the edition number for updated works – indicate the edition number after the title (e.g., 2nd ed. for the second edition of a work). Format the DOI as a URL – this is an update from APA 6th Edition, and is formatted like https://doi.org/10.0000/0000.

REFERENCES

American Psychological Association. (2020). Publication manual of the American Psychological Association (7th ed.). https://doi.org/10.1037/0000165-000