The author-year notation system is required; do not use numbered notation.
Examples:
(Murphy, 2001)
For within-text citations of papers with two authors, name both.
Examples:
(Murphy and Smith, 2001)
With three or more authors, use 'et al.'
Examples:
(Murphy et al., 2001)
For two or more articles using the same within-text citation, add a distinguishing lowercase letter to the year in both the text and references list. Separate citations with a semicolon.
Examples:
(Murphy and Wong, 2001, 2001b; Murphy et al., 2001)
*For citations of multiple works by the same authors, the author names do not need to be repeated.