Columbia subject headings:
Harvard subject headings:
Canada. Royal Canadian Air Force. Squadron, 431--History.
Canada. Royal Canadian Air Force. Squadron, 431--Registers.
Great Britain. Royal Air Force. Bomber Command. Group, No. 6 (RCAF)--History.
World War, 1939-1945--Aerial operations, Canadian.
Princeton subject headings:
Canada. Royal Canadian Air Force. Squadron, 431--History.
Canada. Royal Canadian Air Force. Squadron, 431--Registers.
Great Britain. Royal Air Force. Bomber Command. Group, No. 6 (RCAF)--History.
World War, 1939-1945--Aerial operations, Canadian.