APA requires writers to cite a source by including the last name of the author and year of publication. This rule also applies to articles, books, lectures and sources from digital object identifiers (DOIs). The last name of the author and the date can be cited in the text itself or set off parenthetically.
When citing work by multiple authors, you include all names as well as the year of publication. As with single authors, the last names and date can either be incorporated into the text itself or set off in parentheses. After citing all names the first time, this material can be referenced, in parentheses, by the first author's last name followed by "et al." then the date. If you describe a conclusion agreed upon by many researchers, they must be listed in alphabetical order by last name.
In APA format, websites are cited parenthetically in the text, for example: "APA provides information about careers in psychology (www.apa.org)." With journal articles found on the Internet, you must include the author's last name, year and date of publication in parentheses, for example: (Roberts, 2004, May 4). For information obtained from non-DOI websites, you must include the website, year, month and day retrieved, for example, (www.apa.org, 2011, February 2). Other details about the source are contained in your references at the end of the paper.
Place quotation marks before and after quoted material from a source. Provide the page number in parentheses for the quotation along with the last name of the author(s) and the date of publication. The author's name and the date can be provided in the text itself or parenthetically.