One Work, Six or More Authors

In this example there are six authors: Kosslyn, Koenig, Barrett, Cave, Tang, and Gabrieli (1996)

For the first and subsequent citations write the first author’s name followed by et al.

Narrative

This is how six or more authors would appear as part of a narrative:

Kosslyn et al. (1996)

Parentheses

And if you chose to use parentheses, this is how the citation would look:

(Kosslyn et al., 1996)

(American Psychological Association,  2010, p. 175)