MLA documentation: in-text citations 2
Example:

The student is quoting from page 163 of the following book:

Hentoff, Nat. Listen to the Stories. New York: Harper, 1995. Print.

An interviewer explains that country musician Merle Haggard “is not happy about much that is currently being packaged as ‘country.’ He will name no names but is manifestly disgusted by most of what’s on the charts” (Hentoff 163).

An interviewer explains that country musician Merle Haggard “is not happy about much that is currently being packaged as ‘country.’ He will name no names but is manifestly disgusted by most of what’s on the charts” (163).

If the author is not named in a signal phrase, the author’s last name should be included in the parenthetical citation.