Peter Bower, 'Economic warfare: Banknote Forgery as a deliberate weapon', and Maureen Greenland, 'Compound plate printing and nineteenth-century bank notes, in Virginia Hewitt, ed. ''The Banker's Art: Studies in paper money'', pp 46-63, and pp 84-87, The British Museum Press, 1995, (ISBN 0-7141-0879-0)