CAMEO is Carnegie Mellon University Libraries online catlog. You can search for specific books, or search by subject by selecting "subject" and entering your search (you can combine subject searches as well). Be sure to look at the full Catalog Record to get hints for additional subjects.
Here are some to get you started:
WorldCat provides a quick and easy way to find books and other physical items when you are looking for information on a specific subject. This is a great way to explore the general availability of books on your topic. If you have checked the Library Catalog for a particular book or item and the library does not have it in the collection, search for it here and place an Interlibrary Loan request.