Encyclopaedia of British Pottery and Porcelain Marks by 
New Handbook of British Pottery and Porcelain Marks by 
Miller's Pottery and Porcelain Marks by In addition to these print resources, the Benezit Dictionary of Artists also contains examples of many artists' signatures. An artist's catalog raisonné is also a good place to look for their signature. John Castagno has authored many books on artists' signatures. To search for a complete list in Bobcat, click on Advanced Search, select Author from the drop down menu, and search for "Castagno, John."
African, Asian and Middle Eastern Artists: Signatures and Monograms from 1800 by 
Artists' Monograms and Indiscernible Signatures by 
European Artists: Signatures and Monograms, 1800-1990 by 