Peterson, Philip (23 de junho de 2011). «How Did They Get Here?». Standard Catalog of Military Firearms: The Collector's Price and Reference Guide. Iola, Wisconsin: F+W Media. p. 13. ISBN978-1-4402-2881-0. Consultado em 10 de julho de 2013
world.guns.ruArquivado em 2013-06-18 no Wayback MachineQuote: "almost immediately after the war the GAU issued a new set of requirements for a military and police pistol. These requirements asked for a compact, double action pistol of the Walther PP type...". Recuperado em 27 de abril de 2013.
world.guns.ruArquivado em 2013-06-18 no Wayback MachineQuote: "almost immediately after the war the GAU issued a new set of requirements for a military and police pistol. These requirements asked for a compact, double action pistol of the Walther PP type...". Recuperado em 27 de abril de 2013.