Columbia subject headings:
Blake, George, 1922-2020.
Espionage, Soviet--Great Britain.
Spies--Great Britain--Biography.
Spies--Soviet Union--Biography.
Harvard subject headings:
Princeton subject headings:
Blake, George, 1922-2020.
Espionage, Soviet--Great Britain.
Spies--Great Britain--Biography.
Spies--Soviet Union--Biography.