1. If you name the author in your sentence:
John Parker claims that the elegy nearly died out as an artform in the eighteenth century (31).
The signal phrase—"John Parker claims that"—names the author; the parenthetical citation gives the page number where the quoted words may be found. The period follows the parentheses.
2. If you do not name the author in your sentence:
One study showed that artists-in-residence programs slightly increased the verbal SAT scores of student participants (Ruble 124).
The citation contains the author's last name and the page number, with no punctuation in between.
3. If the author's name is not given in your source:
As of 2001, at least three hundred towns and municipalities had considered legislation regulating the use of cell phones while driving ("Lawmakers" 2).
Use a short form of the title in parentheses, along with the page number of your citation. Titles of books are underlined (or italicized); titles of articles are put in quotation marks. NOTE: If a source is sponsored by an organization (such as the Red Cross) or a government agency, name that organization or agency as the author in your citation.
4. If your source does not have page numbers:
The Department of Transportation points out that existing laws already cover reckless driving related to cell phone use (Jones).
When web sources have no page numbers, use just the author's name in the citation. If a web source such as a PDF file has page numbers, use those in your citation. NEVER put web addresses in parenthetical citations.