To do a Subject search from the library home page, select the Books & More tab (circled in red below), enter your subject in the text box (the example shown highlighted in yellow is Mexico Political Participation), use the drop down box below the text box to select the Subject search (circled in red below), and finally, click the Search button to the right of the text box to view the results.
This will take you to a page in the catalog with subject headings to select from...
If you are having trouble finding books using the subject search, try the keyword search instead.
The subject search will give you results for books that will be about your topic, a keyword search will give you results that mention the word somewhere in the catalog record but may not be as focused as results from a subject search (for example, results from a keyword search might have a chapter that will have information you need instead of the whole book).
If you need help, please contact your Political Science Librarian!