The Williams library catalog is a search engine that lists all the books, videos in the library. It also provides links to articles from selected library databases and citations to articles in the library databases or beyond (to request through interlibrary loan).
To limit your searches to books, you can either
There is no way to limit results to scholarly books. You need to review each book and look at the type of publisher (academic or trade) and the credentials of the author.
Use Williams Worldcat to search for books and films beyond the Williams libraries.