Kelly, Jon (27 Ocak 2011). "The piece of paper that fooled Hitler" 25 Mayıs 2018 tarihinde Wayback Machine sitesinde arşivlendi.. BBC. 1 Ocak 2012 tarihinde erişilmiştir. The Nazis believed Pujol, whom they code named Alaric Arabel, was one of their prize assets.
Kelly, Jon (27 Ocak 2011). "The piece of paper that fooled Hitler" 25 Mayıs 2018 tarihinde Wayback Machine sitesinde arşivlendi.. BBC. 1 Ocak 2012 tarihinde erişilmiştir. The Nazis believed Pujol, whom they code named Alaric Arabel, was one of their prize assets.
Morris, Christopher (1993), "Navy Ultra's Poor Relations", in Hinsley, F.H.; Stripp, Alan, Codebreakers: The inside story of Bletchley Park, Oxford: Oxford University Press, sayfa. 235, ISBN 978-0-19-280132-6
Seaman (2004). "The first code which Garbo was given by the Germans for his wireless communications turned out to be the identical code which was currently in use in the German circuits"