Use Roger to find books, ebooks, films/videos, government publications, etc. about your topic that are available at UC San Diego. Use Melvyl to find books located at one of the ten UC campuses or to request a book from libraries throughout the world.
Begin with a keyword search, for example
women political interest groups
interest groups and elect*
(Note that the * is a truncation symbol, e.g. elect* returns results for election, elected, electing, etc.)
Remember, we most likely do not have entire books devoted to a single interest group, but we may have books on a particular kind of interest groups.
When you find a record for a book that looks useful, take a look at the subject headings. In Roger, these subject headings are clickable links that run a new search. Searching by these subject headings may help find resources that don't turn up with an initial keyword search. They might also give you ideas of other search terms to use in your keyword search.
Bonus search tip: Having trouble finding books using the online catalog? Search the contents of books using Google Books, then do a title search in Roger, Circuit, or Melvyl!
Super bonus tip: Use Google Scholar's "intitle:" limit to search your search term within reference books like encyclopedias, handbooks, dictionaries, etc.