When should I use “et al.” in citations?

The abbreviationet al.” (Latin for “and others”) is used to shorten citations of sources with multiple authors.

In APA Style, “et al.” is used in in-text citations of sources with 3+ authors, e.g. (Smith et al., 2019). It is not used in reference entries.

In MLA style, use “et al.” for 3+ authors in in-text citations and Works Cited entries.

In Chicago style, use “et al.” for 4+ authors in an in-text citation, and for 10+ authors in a bibliography entry.