Fernau, Curt Nicolaus - 'Squared Circle' Postmarks Used Outside Great Britain
An OverviewPublisher: Great Britain & Commonwealth Philatelic Society (Switzerland), 2003.
First edition, paperback, 44 pages, Fine condition.
A superb summary of the various types of squared circle postmarks and the more than 30 countries, from Aden to Zanzibar, which used them. The countries which adapted the British postmark for their own use were mainly in the British Empire, but also included here are Hawaii, Dutch Colonies, and Italy. Well illustrated, and containing a mass of information gathered together in one volume for the first time. 
