Columbia subject headings:
Harvard subject headings:
Diplomatic and consular service--Poland.
Espionage, Polish--History--20th century.
Espionage--Poland.
Intelligence service--Poland--History--20th century.
Poland--Foreign relations--1945-1989
Poland. Służba Bezpieczeństwa--History--20th century.
Princeton subject headings:
Intelligence service--Poland--History--20th century.
Internal security--Poland--History--20th century.
Poland. Urząd Bezpieczeństwa--History.