Columbia subject headings:
Poland--History--Occupation, 1939-1945--Sources.
World War, 1939-1945--Poland--Sources.
Harvard subject headings:
Poland--History--Occupation, 1939-1945--Sources.
World War, 1939-1945--Poland--Sources.
Princeton subject headings:
Poland--History--Occupation, 1939-1945--Sources.
World War, 1939-1945--Poland--Sources.