Use in-text parenthetical citations whenever you are using someone else's ideas or words in your paper (paraphrasing or quoting). Each in-text citation corresponds to an entry in your Works Cited page.
All you need to know is the first part of your Works Cited entry (usually the author's last name) and the location (usually a page number).
In-text citations go at the end of a sentence that includes a quotation or a paraphrase, like this:
This is a paraphrase (Nunberg, 83).