Try looking the artist (picasso, pablo) up as both a subject, and as an author in the Library Search, or try the artist as a keyword search (pablo picasso).
To verify the spelling of an artist's name, as well as to find more information in journal articles, consider using the browse function of Art Full Text .
The Union List of Artist Names, or ULAN, is another excellent way to verify the spelling of an artist's name.
Try Oxford Art Online. You will find wonderful articles written by experts on the subject, plus bibliographies of books and articles you can use as a starting point for your research.
More resources can be found in the Sherman Reference Room