Reference books such as encyclopedias, dictionaries and bibliographies will provide you with background information, definitions, or lists of references relating to a particular subject, time period, region, author etc.
Search in the library's catalogue to find ecyclopedias, dictionaries, bibliographies, and more.
Tip: search for your topic AND a word to describe the type of item you're looking for, such as encyclopedia, dictionary, etc.
For example, if you search for political theory AND encyclopedia, you'll find the following item:
Political, economic, social, statistical and/or legal information on any country of the world:
Economist Intelligence Unit (EIU)