James P. Duffy: Target: America. Hitler’s Plan to Attack the United States. Lyons Press, New York NY 2006, ISBN 1-59228-934-7, S. 116 und 175. Ursprüngliche Quelle: Irregularities Connected with the Handling of Surrendered German Submarines and Prisoners of War at the Navy Yard, Portsmouth, New Hampshire, SecNav/CNO file A16-2(3) EF30, Record Group 80; National Archives USA (U-873 online einsehbar bei Uboatarchive.net).
