The library's catalog is one of the best places to start your search for books on your subject. Unlike Discovery, it does not include journal articles in its results.
If you're at the library, you can also try browsing the shelves. We use the Library of Congress (LC) classification system, which arranges library materials by subject. Here are a few Hispanic Heritage-related LC call number ranges:
If the library doesn't have the book you need, try requesting it through Interlibrary Loan!