The author's last name and the work's date of publication must always appear & are all that is necessary when citing an idea, an entire book, article or other work.
Example: (Smith, 2009)
The page number appears only if it is a direct quotation.
Example: (Smith, 2009, p. 195) or (Smith, 2009, pp.195-196)
For more information, click on the link to APA In-Text Citations: The Basics or on the link for In-Text Citations: Author/Authors from the OWL at Purdue.