Most Theatre books have a Library of Congress call number in the PN section on Reynolds 5, though playscripts and some historical studies will be shelved in their respective literature sections (PA for Greek & Latin, PQ for French, Spanish & Italian, PR for British, PS for American). Some call number sections to look at include:
Each book record in the online catalog also contains Library of Congress Subject Headings, which can help you locate books on a similar topic. Click on the subject heading in the online catalog to go to a list of books that share that subject heading. Some examples are:
The names of individual playwrights, actors, plays and theatres are also included as subject headings: