Collecting Costume Jewelry 202: The Basics of Dating Jewelry 1935-1980, Identification and Value Guide Paperback – Illustrated, September 5, 2006: Amazon.com: Books
Schiaparelli brooch with older, lower case block letter signature. Used from the 30s until 1949 according to "… | Vintage jewelry, Block lettering, Costume jewelry
Ten Books for Lovers of Vintage Costume Jewelry – 24 Wishes