Columbia subject headings:
Petroleum industry and trade--Caribbean Area--History--20th century.
World War, 1939-1945--Campaigns--Caribbean Area.
World War, 1939-1945--Naval operations, German.
World War, 1939-1945--Naval operations--Submarine.
Harvard subject headings:
Military campaigns.
Petroleum industry and trade
Petroleum industry and trade--Caribbean Area--History--20th century.
World War, 1939-1945--Campaigns--Caribbean Area.
World War, 1939-1945--Naval operations, German.
World War, 1939-1945--Naval operations--Submarine.
Princeton subject headings:
Petroleum industry and trade--Caribbean Area--History--20th century.
World War, 1939-1945--Campaigns--Caribbean Area.
World War, 1939-1945--Naval operations, German.
World War, 1939-1945--Naval operations--Submarine.