There are no authors of individual chapters.
Smith, M. J., & Liehr, P. R. (Eds.).
Title of book is italicized:
Middle range theory for nursing.
If there is an edition other than the first:
City & State the book is published in:
New York, NY:
Retrieved from http://www.r2library.com.
American Psychological Association, 6th edition.
7.02 Books, Reference Books & Book Chapers, pp. 202-205.