Give the author of the source, the year of publication and if available and a page number in parentheses for e-text citations. The Diana Hacker Rules for Writers Handbook gives the following example: "Yanovski and Yanovski (2002) reported that....."
Note that since the text states the authors' names within the paper, all you need in parentheses is the year of publication. If directly quoting the above without stating the author in the sentence, you would write the quote and cite it as follows: "The current state of the treatment for obesity is similar to the state of the treatment" (Yanovski & Yanovski, 2002).
Note the period end mark follows the parenthetical citation. Also, note a comma separates the author's name from the year. If a page number is involved, the entry would read as follows: "The current state of the treatment for obesity is similar to the state of the treatment" (Yanovski, 2002, p. 600).
Name both authors each time you cite the work if there are two authors. If you are quoting them within the text, join their names with "and"; however, if you are citing their names in parentheses, join them with "&". For example, using the source from Step 1: "Yanovski and Yanovski ((2002) reported that..." or "The current state of the treatment of obesity is similar to the state of the treatment" (Yanovski & Yanovski, 2002).
Cite all the authors for e-text in-text citations with three to five authors the first time you cite the work, but in future references within the paper only cite the first author's name followed by et al. For example: "Thomas, Billows and Carnes (2009) state..." or "Thomas et al. (2009) refer to this as..."
Et al. means "and others" in Latin. Note that there is no period after the "et," only after the "al" as "al" is an abbreviation of "alia."
Use just the first author's name throughout the paper for an e-text parenthetical citation with six or more authors, including the first time you use the source. For example: "Jones et al. (2008) provides the following..."
List the first word or two of the title for APA e-text in-text citations without authors. For example: "Indications of obesity in children..." (USA Today, 2002).
If the author is an organization such as a government agency or familiar organization, such as The American Cancer Society it would be cited as follows: "Indications of obesity in children..." (American Cancer Society [ACS], 2010).
Note the brackets in the example above. If the abbreviations are familiar, they can be used for further in-text citations instead of the entire name.