Helge Moe and Tor Glad, two Norwegians Peppermint – José Brugada Puppet – Mr Fanto, a Briton Rainbow – Günther Schütz Rover Scruffy – Alphonse Timmerman Shepherd The Snark – Maritza Mihailovic, a Yugoslavian Sniper Snow – Arthur Owens Spanehl – Ivan Španiel Spider – based in Iceland Springbok – Hans von Kotze Stephan – Klein Summer – Gösta Caroli Sweet William – William Jackson Tate – Wulf Schmidt Teapot Treasure – Nathalie Sergueiew (Lily Sergeyev) Tricycle – Dušan Popov Washout – Ernesto Simoes Watchdog – Werner von Janowski Weasel – A doctor, Belgian The Worm – Stefan Zeiss Zigzag – Eddie Chapman Notes References Bibliography Note: Ordway/Sharpe cite Masterman Further reading Hinsley, F. H., and C. A. G. Simpkins. British Intelligence in the Second World War, Volume 4, Security and Counter-Intelligence. London: H.M. Stationery Office, 1990. . Howard, Michael British Intelligence in the Second World War, Volume 5, Strategic Deception London: H.M. Stationery Office, 1990. . John C. Campbell, "A Retrospective on John Masterman's The Double-Cross System", International Journal of Intelligence and CounterIntelligence 18: 320–353, 2005. Jon Latimer, Deception in War, London: John Murray, 2001. Public Record Office Secret History Files, Camp 020: MI5 and the Nazi Spies, Oliver Hoare, 2000. Tommy Jonason & Simon Olsson, "Agent Tate: The Wartime Story of Double Agent Harry Williamson", London: Amberley Publishing, 2011. . Benton, Kenneth . "The ISOS Years: Madrid 1941-3". Journal of Contemporary History 30 (3): 359–410, 1995. Fiction. Overlord, Underhand'' (2013), by the American author Robert P. Wells is a fictionalized retelling of the Juan Pujol (Garbo) double-agent story from the Spanish Civil War through 1944, examining his role in MI5's Double-Cross System. . Espionage techniques