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.
"Currencies of the World". University of British Columbia. May 1 2008. Archived from the original on ۲۹ نوامبر ۲۰۱۱. Retrieved 3 May 2013. Check date values in: |تاریخ= (help)