As we all know, the correct number of authors for any work is one. This makes it really simple to cite and reference, saving us time and therefore is objectively the best number. Authors are however gregarious folk who often like to write articles, books and other works collaboratively with no thought for how much this will complicate your attempts at referencing. For other sources, no author can be identified. This is where life gets fun.
This post explains what to do when faced with an unhelpful number of authors in APA (6th ed.) referencing.
The first few words of the title are used in the citation, as described in this blog post. For a journal article or a blog post, use the title of the article or post itself not the title of the journal or blog it appears in. In the reference list, the title moves to the start of the reference, in place of the missing author name.
In-text citations should list all the authors every time.
For two authors, join the names with an ampersand (&). For three or more authors, always precede the last author with a comma and an ampersand (&), for example:
Simpkins & Tolomson (2016, p. 216) found
Smith, Jones, & Swanson (2006, p. 4) suggest…
In the reference list, the last author is always preceded by a comma and an ampersand, regardless of the number of authors, for example:
Simpkins, T. J., & Tolomson, K. (2016). Strange findings in plants. Journal of Peculiar Plant Biology, 64(3), 24-37.
4 or more authors
The pattern for citing and referencing remains the same as for three authors. The only difference is if and when you have to list all the authors’ names in in-text citations. All the authors must be listed in the reference list entry, regardless of how many there are or how annoying this might be.
You have to list all the authors the first time that you cite them. In your second and subsequent citations for the same work, you can use “et al.” (an abbreviation of the Latin et alia, meaning “among others”) in place of all the other author names. For example:
First time a work with 4-5 authors is cited
Worden, Collinson, Weston, & Friggens (2015)
Whenever the same work is cited after this in the text
Worden et al. (2015)
6 or more authors
You only ever have to give the first author’s name in a citation for anything written by six or more authors. Every time you cite the work, give the first author’s name followed by et al., for example if Adler and eighteen collaborators were named as authors for a work, you would cite it every time as:
Adler et al. (1926)