American & German helmets & body armor of World War One / by Bashford Dean ; ed. by Hayes Otoupalik, Dennis Gordon, Paul J. Schulz osprey military warrior series German Stormtrooper : 1915-18 / Ian Drury ; illustrated by G. Embleton elite series U-boat crews : 1914-45 / Gordon Williamson ; ill. by D. Pavlovic Imperial German edged weaponry / Thomas M. Johnson with Victor Diehl & Thomas Wittmann