Columbia subject headings:
Harvard subject headings:
Germany. Kriegsmarine--Biography.
Germany. Kriegsmarine--Medals, badges, decorations, etc.--Registers.
Military decorations--Germany--Registers.
Ritterkreuz.
Submarine captains--Germany--Biography.
Submarines--Germany--History--20th century.
World War, 1939-1945--Medals--Germany--Registers.
World War, 1939-1945--Naval operations, German.
World War, 1939-1945--Naval operations--Submarine.
Princeton subject headings:
World War, 1939-1945--Campaigns--Atlantic Ocean.
World War, 1939-1945--Naval operations, German.
World War, 1939-1945--Naval operations--Submarine.