Student's guide to writing college papers, Fourth edition - Kate L. Turabian 2010

What to include in a citation
Citations
Citing sources

Although the Chicago, MLA, and APA styles format citations differently, they have the same goal: to give readers the information they need to identify and find a source. For most sources, that information must answer three questions:

1. Who is responsible for the text?

This is usually the author, but it might also be an editor, a translator, or an organization.

2. What's the name of the text?

This includes the title and subtitle of the work itself. If the work is part of a series or multivolume collection, it includes that title as well.

3. Who published it, where, and when?

For an article, this includes the title of the journal or magazine as well as a volume number and the page numbers of the article. For a book, it includes the publisher and the place of publication. For a website, it includes the sponsoring organization and the URL. For articles and books, this also includes the date of publication; for websites, it usually includes the date you accessed it.

With this information, readers can almost always identify and find the specific source in your citation.