Columbia subject headings:
Harvard subject headings:
Cold War--Secret service--Europe, Central--History--20th century--Congresses.
Cold War--Secret service--Europe, Eastern--History--20th century.
Espionage, Soviet--Europe, Central--History--20th century--Congresses.
Espionage, Soviet--Europe, Eastern--History--20th century--Congresses.
Espionage--Europe, Central--History--20th century--Congresses.
Espionage--Europe, Eastern--History--20th century--Congresses.
Intelligence service--Europe, Central--History--20th century--Congresses.
Intelligence service--Europe, Eastern--History--20th century--Congresses.
Princeton subject headings:
Cold War--Secret service.
Espionage, Soviet.
Espionage--Europe--20th century.
Intelligence service--Europe--20th century.