Columbia subject headings:
Harvard subject headings:
Cold War--History.
Radio broadcasting--Political aspects--Germany (East)--History.
Radio broadcasting--Political aspects--Germany (West)--History.
Radio in propaganda--Germany (East)--History.
Radio in propaganda--Germany (West)--History.
Princeton subject headings:
Cold War--Cryptography.
Cold War--Electronic intelligence--Germany.
Cold War--Secret service--Germany.
Electronic intelligence.