When OneSearch to search for books, it's ok to do a quick search (which by default, is a keyword search), but another powerful way to focus your search is by using a subject search (advanced search and change "any field" to "subject"). For example, click on the links below examples. Remember that the subject is what the book is "about," so if you're looking for books about an artist, search that person's name as a subject. Searching for an artist as author will give you results that include catalogs (such as exhibition catalogs and Catalogues Raissonné).
Examples of relevant subject searches:
Beauford Delaney (artists as subjects)
Fluxus (movements as subjects)
BROWSING the subject "abstract expressionism" (take a look at what related subjects you can find doing a subject browse)