Columbia subject headings:
Harvard subject headings:
Navy-yards and naval stations--France--History--20th century.
Navy-yards and naval stations--Germany--History--20th century.
Navy-yards and naval stations--Norway--History--20th century.
Submarines (Ships)--Germany--History--20th century
World War, 1939-1945--Naval operations, German.
World War, 1939-1945--Naval operations--Submarine.
Princeton subject headings:
Germany. Kriegsmarine
Navy-yards and naval stations--Germany--History--20th century.
World War, 1939-1945--Naval operations, German.
World War, 1939-1945--Naval operations--Submarine.