APA citation style - 6th edition
On this page
- In most cases, providing the author's last name and the publication year are sufficient:
Smith (1997) compared reaction times...
Within a paragraph, you need not include the year in subsequent references.
Smith (1997) compared reaction times. Smith also found that...
- If there are two authors, include the last name of each and the publication year:
...as James and Ryerson (1999) demonstrated...
...as has been shown (James & Ryerson, 1999)...
3 - 5 authors
- If there are three to five authors, cite all authors the first time; in subsequent citations, include only the last name of the first author followed by "et al." and the year:
Williams, Jones, Smith, Bradner, and Torrington (1983) found...
Williams et al. (1983) also noticed that...
- The names of groups that serve as authors (e.g. corporations, associations, government agencies, and study groups) are usually spelled out each time they appear in a text citation. If it will not cause confusion for the reader, names may be abbreviated thereafter:
First citation: (National Institute of Mental Health [NIMH], 1999)
Subsequent citations: (NIMH, 1999)