The American Psychological Association (APA) has its own style for citing sources in research papers. APA style has strict rules for citing websites and other research documents. Writers must cite any webpage used in research at least twice throughout their paper--once after the information quoted or paraphrased in the text of the paper (known as an "in-text" citation) and once on the reference list at the end of the paper.
Use this format for citing a webpage in the reference list at the end of the paper (without the brackets): [Author Last Name, First Initial. Middle Initial. (Date of publication). Title of Page/Document (italicized). Retrieved from URL.] Use the author's first and middle initials instead of his full name. If no author is available, begin the citation with the title of the webpage or document. If no publication date is available, use n.d. For example, a citation for the article "Penn Football Player Had Brain Disease, Autopsy Shows" from the New York Times website would look like: Schwarz, A. (Sept. 13, 2010). Penn Football Player Had Brain Disease, Autopsy Shows (italicized). Retrieved from http://www.nytimes.com/2010/09/14/sports/14football.html?_r=1&hp.
Use this format to cite a webpage in the text of your paper: (Author, year, page number if applicable). Use parentheses around the text of the citation. If there is no author, use the first one or two words of the title. If there is no date, use n.d. Place the citation at the end of the sentence(s) to which it refers, i.e. "cited material" (citation). For the article cited in step one, the in-text citation would be: (Schwarz, 2010).
Refer to the American Psychological Association's Publication Manual of the American Psychological Association (6th ed) if you need clarification on the above formats. The manual is the definitive source for APA style citation.