Columbia subject headings:
Harvard subject headings:
Espionage, Soviet--Great Britain.
Rees, Goronwy, 1909---Biography.
Spies--Great Britain--Biography.
Princeton subject headings:
Authors, Welsh--20th century--Biography.
Espionage, Soviet--Great Britain.
Rees, Goronwy, 1909-1979--Biography.
Spies--Great Britain--Biography.