Try a keyword search. Once you find a book that is relevant to your topic, use the subject terms of that book to help you find "more like this."
Example: In the Wellesley College Library catalog -- the catalog is the second search box on the LTS homepage at http://new.wellesley.edu/lts:
change "Title" to "Keyword" and search "Satyagraha" (the nonviolent movement in India and South Africa)
Find a good book from the list of results, click on the title to see the full record, and look for list of subject terms that describe the book's contents. Follow these links to find all the books on your topic.
Subject terms for books from this keyword search include
Not finding enough, or found an item that's checked out? Search WorldCat and request a copy.