These sources are good for current reviews of a body of academic scholarship:
For broader context in political theory or philosophy or for useful articles on key concepts in political theory/philosophy, consult these references:
When searching the Main Catalog, take a look at subject headings for ideas to extend or narrow your search. You can search in the subject headings, using the Guided Search form.
To get more focused results, search phrases within quotation marks. To broaden your search, use a question mark ? to search for alternative endings and spellings of words (e.g., philosoph? will pick up philosophy, philosopher, philosophical, etc.).
You're not just limited to what Princeton owns, however. The library can get you books from libraries around the world. This can be helpful when you have a very specialized topic or you're just not finding much in the main catalog. To search for books at other libraries, try Borrow Direct or the more comprehensive WorldCat.