To find books at the UMass Libraries, use the Five Colleges Library Catalog and select the UMass link. Be as specific as possible in your searching. Start with a subject search (use keywords if subjects yield no results). Try broad categories, browsing the sub-topics. Try the Advanced Search option and limit by date,language, format or with additional words.
If UMass doesn't have the book(s) you need, try the other Four Colleges.
If the book is not available in the Five College Library System, you may order it through InterLibrary Loan.