Columbia subject headings:
Great Britain. Royal Navy. Fleet Air Arm--Biography.
John, Caspar, 1903-1984.
Harvard subject headings:
Great Britain. Royal Navy. Fleet Air Arm--Biography.
John, Caspar, 1903-1989.
Princeton subject headings:
Great Britain. Royal Navy. Fleet Air Arm--Biography.
John, Caspar, 1903-1984.