ARTIST AS AUTHOR: In the library catalogs, works of authorship for artists can include art exhibition catalogs, books where the main focus in on publishing art reproductions of the artists, as well as textual or literary works of authorship by an artists (essays, lectures, letters, etc.). These include primary resources.
SUBJECT: Works primarily about an artist (monographs, scholarship about an artist, etc.) are classified by subject.
Try both approaches, or use keyword or phrase searching -- e.g. James McNeill Whistler -- when looking in the library catalog.