American Psychological Association (APA) style is used most often if you are a student majoring in psychology or the social sciences. Most papers from these disciplines incorporate original research or literature written on previous research. APA style is a way to document these research sources using in-text citations and a list of references.
An APA in-text citation requires that you provide at least an author's last name and the year of publication. This is usually done by using a phrase that signals you are presenting information that comes from a research source. For example, you could introduce a 2004 medical research study by writing "Green and Golden (2004), medical researchers, claimed that 'the drug worked in more than half of the patients on whom it was tested.'" APA requires you to use the past tense ("claimed") or the present perfect tense ("has claimed") when introducing research material. Also, even if you know the month in which a study was published, include only the year of publication in the in-text citation.
At the end of the sentence containing the quoted material, place the page number on which the information can be found. The page number is enclosed in parentheses and preceded by "p": "Green and Golden (2004), medical researchers, claimed that 'the drug worked in more than half of the patients on whom it was tested' (p.104)."
If you have not named the author before giving the quote from the research source, that information should be placed in parentheses before the page number: "Medical researchers claimed that 'the drug worked in more than half of the patients on whom it was tested' (Green & Golden, 2004, p. 104).
An alphabetical list of all the research sources used in the essay appears at the end of the work and should be titled "References." Generally, each entry is alphabetized by the last name of the author. If a source has no author, begin the entry with its title. A reader should always be able to match the in-text citation to this first element of the reference page entry. The date of publication is given after the first element of the reference page entry. What follows the first element and date depends on the type of research source that is in use. Consult the "Publication Manual of the American Psychological Association" to find the exact reference-entry format that is needed for your type of research source.