if you're using MLA, follow this:
Citing Multiple Works by the Same Author
If you cite more than one work by a particular author, include a shortened title for the particular work from which you are quoting to distinguish it from the others.
Lightenor has argued that computers are not useful tools for small children ("Too Soon" 38), though he has acknowledged elsewhere that early exposure to computer games does lead to better small motor skill development in a child's second and third year ("Hand-Eye Development" 17).
Additionally, if the author's name is not mentioned in the sentence, you would format your citation with the author's name followed by a comma, followed by a shortened title of the work, followed, when appropriate, by page numbers:
Visual studies, because it is such a new discipline, may be "too easy" (Elkins, "Visual Studies" 63).
if you need any more help with citations, go to http://owl.english.purdue.edu/owl/resource/557/03/
it's a great site
Shannon Woodward