Columbia subject headings:
Harvard subject headings:
Germany. Geheime Staatspolizei
Poland--History--Occupation, 1939-1945
World War, 1939-1945--Secret service--Poland.
World War, 1939-1945--Underground movements--Poland.
Princeton subject headings:
Poland. Polskie Siły Zbrojne. Armia Krajowa
World War, 1939-1945--Underground movements--Poland.