Columbia subject headings:
Harvard subject headings:
Cold War
Espionage, Communist--Switzerland--Case studies.
Espionage, Communist--Switzerland--History.
Espionage, East German--Switzerland--Case studies.
Espionage, East German--Switzerland--History--20th century.
Espionage, East German--Switzerland--History.
Germany (East)--Relations--Germany (West)
Germany (East). Ministerium für Staatssicherheit--Case studies.
Germany (East). Ministerium für Staatssicherheit.
Germany (West)--Relations--Germany (East)
Secret service--Germany (East)--Case studies.
Secret service--Germany (East)--History
Spies--Germany (East)--Case studies.
Spies--Switzerland--Case studies.
Princeton subject headings:
Espionage, Communist--Switzerland--History.
Espionage, East German--Switzerland--History.
Germany (East)--Relations--Germany (West)
Germany (East). Ministerium für Staatssicherheit
Germany (West)--Relations--Germany (East)
Secret service--Germany (East)--History.