Initial use of search engines designed to access a large volume of materials can be helpful in scanning the literature on a particular topic and obtaining an initial understanding of how scholars, journalists, and others have studied your topic of interest. The USC Libraries' search engine only accesses materials owned by the library, but it can be a good place to obtain background information from a variety of scholarly and non-scholarly sources. Google Scholar covers a much broader array of [mostly] scholarly resources but not everything you find may be accessible.
The search option on the USC Libraries main web page provides a single search box with comprehensive access to print and online books, selected digital resources, and full-text journal, magazine, and newspaper articles owned by the USC Libraries or accessible online through subscriptions. Information about using the Libraries' search engine can be found here.
Google Scholar provides access to mostly scholarly [i.e., peer-reviewed, academic] sources, including scholarly titles from Google Book Search. The search engine has a "Cited by" featurethat allows you to track where a particular source has been subsequently cited after publication.
The following databases can help you search for literature that identifies and describes political theories, topics, or issues.
Annual Reviews -- provides scholarly, in-depth review articles on a variety of topics ranging from basic sciences to the social, behavioral, and clinical sciences. The reviews provide a comprehensive introduction to new research topics.
CQ Researcher -- in-depth, unbiased coverage of the political and public policy aspects of healthcare, social trends, criminal justice, international affairs, education, the environment, technology, the economy, and much more. Reports are published 44 times a year.
Credo Reference -- comprehensive collection of highly-specialized reference works, primarily dictionaries and encyclopedias, across all subject areas. Good place to go for succinct definitions and explanations of concepts, theories, or issues.
Oxford Research Encyclopedias-- offers comprehensive overview articles written, peer-reviewed, and edited by leading scholars on topics in a wide range of social science disciplines.
Descriptions of resources are adapted or quoted from vendor websites.