Krause, Chester L., and Clifford Mishler (1991). Standard Catalog of World Coins: 1801–1991 (18th ed. ed.). Krause Publications. ISBN0873411501.
Pick, Albert (1994). Standard Catalog of World Paper Money: General Issues. Colin R. Bruce II and Neil Shafer (editors) (7th ed.). Krause Publications. ISBN0-87341-207-9.