Columbia subject headings:
KC PZPR--History--Sources.
Poland--History--1945-1980--Sources.
Poland--Politics and government--1945-1980--Sources.
Harvard subject headings:
Poland--History--1945-1980--Sources.
Poland--Politics and government--1945-1980--Sources.
Polska Zjednoczona Partia Robotnicza--History--Sources.
Polska Zjednoczona Partia Robotnicza. Biuro Polityczne--History--Sources.
Strikes and lockouts--Poland--History--Sources.
Princeton subject headings: