For example, Frankestein's Monster may have a listing all its own. This will set up you to research books. Photocopy the pages you find in the Index. In addition to books, you'll want to find academic journals. Not every topic has a book written about it.
Journals contain original research, and, equally important, citations of earlier work.
There are several different Journal indexes. You'll have to find the specialty indexes which relate to the types of academic Journals you are interested in. Look at the list of Journals the library carries. Find out which Index catalogs this Journal. You'll want to ask a reference librarian for suggestions on which indexes to search.