Birdsall, Harry. 1961. 3-Cushion Angle System. Jacksonville, IL: H.A. Birdsall. Very rare but excellent booklet on the diamond system. This book is a first edition and has some spotting on the cover. Birdsall was famous in the Midwest amongst billiard players as being a system expert. Book endorsed by “Professionals” including Juan Navarra of Argentina, Norm Ross of Indiana, and the recently deceased Bill Hawkins of Decatur, IL. The book is not much in terms of bulk, but it is a highly sought after booklet on billiards.