Columbia subject headings:
Naval convoys--History--20th century.
World War, 1939-1945--Campaigns--Atlantic Ocean.
Harvard subject headings:
Naval convoys--History--20th century.
World War, 1939-1945--Campaigns--Atlantic Ocean.
Princeton subject headings:
Naval convoys--History--20th century.
World War, 1939-1945--Campaigns--Atlantic Ocean.