Use more general terms for books than the more specific terms needed for searching for articles. Limit your search scope to UO Libraries.
You may get more or better results if you do a Subject Heading search for a broad term. Using the pull-down menu to the left of the search bar on the Libraries home page or in Advanced Search, select Subject. You also can click on the subject heading links in the "details" display for a book that you like, to get more like it.
Here are some terms used in LC Subject Headings for that you can search on. (Remember, subject terms for books are usually more general / broad, because books cover so much more than articles.)