American Psychological Association style is a widely accepted style of documentation, particularly in the social sciences. APA style specifies the names and order of headings, formatting, and organization of citations and references, and the arrangement of tables, figures, footnotes, and appendices, as well as other manuscript and documentation features. APA style uses the author-date style of parenthetical referencing, with such source citations keyed to a subsequent list of references. Also known as the Harvard style, the APA Publication Manual provides basic guidelines for documenting both print and electronic resources. The section on electronic resources is updated and supplemented by the APA Style Guide to Electronic References. The sixth edition was published by the American Psychological Association in July 2009. It offers new and expanded guidelines.