Columbia subject headings:
Harvard subject headings:
Arms race--Europe--History--20th century.
Salvage--Scotland--Scapa Flow--History--20th century.
Scapa Flow Scuttling, Scotland, 1919.
World War, 1914-1918--Naval operations, German
Princeton subject headings:
Germany. Kriegsmarine--History.
World War, 1914-1918--Naval operations.