Cambridge Companions Online offers subject or theme based collections of content within a fully cross-searchable online environment, covering literature, classics, philosophy, religion, and cultural studies.
Access: On or off campus
Reference Books are sources like encyclopedias or dictionaries that contain a large-scale overview of many subjects, often on a single topic. Reference Books are located in the Webster Reference Room on the first floor of the Library Learning Commons. Generally, they may be used in the library but are not available for loan. Use a reference source when you are unfamiliar with a topic and want a good introduction or when you want to find an authoritative opinion about a general topic.
There are many more Reference books available for English Literature, but these are some good general ones. Oxford and Cambridge each publish many wonderful Reference works in Literature, which can be accessed through Oxford Reference Online and Cambridge Collections Online respectively.
Brewer's Dictionary of Phrase and Fable by 
A Glossary of Contemporary Literary Theory by 
