Columbia subject headings:
Harvard subject headings:
Merchant marine--Mediterranean Sea--History--20th century.
World War, 1914-1918--Campaigns--Mediterranean Sea
World War, 1914-1918--Naval operations
Princeton subject headings:
Merchant marine--Mediterranean Sea--History--20th century.
World War, 1914-1918--Campaigns--Mediterranean Sea.
World War, 1914-1918--Naval operations.