Columbia subject headings:
Harvard subject headings:
Poland--History--Occupation, 1939-1945--Sources.
Poland--Relations--Soviet Union--Sources.
Soviet Union--Relations--Poland--Sources.
Soviet Union. Narodnyĭ komissariat vnutrennikh del--History--Sources.
World War, 1939-1945--Prisoners and prisons, Russian--Sources.
World War, 1939-1945--Underground movements--Poland--Sources.
Princeton subject headings:
Poland--History--1945-1980--Sources.
Poland--Relations--Soviet Union--Sources.
Soviet Union--Relations--Poland--Sources.
Soviet Union. Narodnyĭ komissariat vnutrennikh del--History--Sources.
Subversive activities--Poland--History--Sources.