Columbia subject headings:
Cold War.
Espionage, British--Germany (East)
Spies--Germany (East)
Spies--Great Britain.
Harvard subject headings:
Cold War
Espionage, British--Germany (East)
Spies--Germany (East)
Spies--Great Britain.
Princeton subject headings:
Cold War.
Espionage, British--Germany (East).
Spies--Germany (East).
Spies--Great Britain.