Columbia subject headings:
Harvard subject headings:
Germany (East). Ministerium für Staatssicherheit--History.
Intelligence service--Germany (East)--History.
Secret service--Germany (East)--History
Secret service--Western countries--History.
Princeton subject headings:
Germany (East). Ministerium für Staatssicherheit--History.
Intelligence service--Germany (East)--History.
Secret service--Germany (East)--History.
Secret service--Western countries--History.
Spies--Germany (East).