The Baltimore Sabotage Cell: German Agents, American Traitors, and the U-boat Deutschland During World War I: Messimer, Dwight R.: 9781591141846: Amazon.com: Books
Deutsche Uboote seit 1956: Karr, Hans: 9783613037083: Amazon.com: Books
U-48: The Most Successful U-Boat of the Second World War: Franz Kurowski: 9781848326064: Amazon.com: Books