The resources on this page will help you to get an overview of scholarly work on your topic.
Encyclopedia articles can be very helpful. Try these two roads into specialized encyclopedias:
An literature review article will help you get an overview of the research that's been done on a theoretical question.
These sources publish review articles exclusively.
Dissertations can be good sources for literature reviews, and in some cases may represent the only literature on a highly focused topic.
Search for dissertations via ProQuest Dissertations & Theses. In most cases, dissertations from 1997 and later can be downloaded in full text.