The first part of an internal citation should be the first word or words of the reference on the "References" page, that way anybody reading the article can easily find the source. Usually, it is the author, but if there is no author, start with the first part of the citation. The following are examples of in-text citations that were not preceded by any other information, such as the author's name. If this information is previously mentioned, there is no need to include it in the citation.
Example:
In 1999, Smith and Jones concluded that the research method was flawed (p. 120).
or
As Smith and Jones stated, "The methods used in previous analysis resulted in inconclusive and incorrect data as compared to other methods" (1999, p. 120).
For basic internal APA citation formatting, see the following list:
Works by one author
(Castro, 1983, p. 233)
Works by two authors
(Townsend & Barker, 1999, p. 24)
Works by three to five authors*
(Woods, Smithers, & Bradbury, 2006, p. 3)
*Note: In works by three to five authors, use the last name of the first author followed by et al. as shown in the next example.
Works by six or more authors
(Woods et al., 1988, p. 112)
Works from a secondary source
(as cited in Shockey, 1994, p. 54)
Works with no author
("Finding Balance," 1982)
Government documents
(United States Forest Service, 1992)