APA is outlined in Publication Manual of the American Psychological Association, 6 ed., and is commonly used in the behavioral and social sciences.
APA is an author-date style, which means that you make in-text citations by placing the author's surname and the year of publication within parenthesis. If you mention the author in a sentence or passage, it is custom to place only the year within parenthesis. Ampersand (&) is only used in in-text citations and in the bibliography, not in the body of the text. If you are citing a source word for word, you should include a page number in the in-text citation. A few examples:
When citing two or more sources in a sentence or passage, you list your sources alphabetically and separated by semicolon in the in-text citation:
Both surnames are included each time you cite the source:
All surnames are included the first time you cite the source. Thereafter, only cite the first surname followed by et al. and the year:
Only cite the first surname followed by et al. and the year:
All references cited in your text should be included in the bibliography. The sources are sorted in alphabetical order by surname or organisation name. If no surname nor organisation name is available, the reference is sorted by title.
In APA, the first line of a reference is left aligned, with subsequent lines indented to the right by 5-7 spaces or 1.25 cm.
All authors are listed in the bibliography:
The first six authors are listed, then a three dot elipse followed by the last author: