Library books at CSUSB are cataloged with Library of Congress Subject Headings. To explore items catalogued under the subject of printmaking, you may want to use the following subjects in your searches: prints, prints--technique as well as the type of printmaking you're interested in: Lithography, Wood-engraving, Relief printing, etc..
Though the online catalog is a great tool, sometimes it's helpful to go and browse the resources in the library. If you choose to do this, you might want to start in the following call number ranges: NE400-773 (history and artists), NE1000-1352 (Wood engraving), NE1400-1879 (Metal engraving), NE1940-2232.5 (Etching and aquatint), NE2236-2240.6 (serigraphy, a.k.a. silk screen), NE2250-2570 (Lithography).