Columbia subject headings:
Harvard subject headings:
Concentration camps--Poland--History--20th century.
Dictatorship--Poland--History--20th century.
Forced labor--Poland--History--20th century.
Poland--History--1945-1980
Political persecution--Poland--History--20th century.
Political prisoners--Poland--History--20th century.
Prisons--Poland--History--20th century.
Prisons--Poland--Social conditions.
Princeton subject headings:
Poland--History--1945-1980.
Political persecution--Poland--History--20th century.
Political prisoners--Poland--History--20th century.
Prisons--Poland--History--20th century.