Columbia subject headings:
Poland--History--Occupation, 1939-1945.
Poland--Relations--Soviet Union.
Soviet Union--Relations--Poland.
Harvard subject headings:
Germany--Foreign relations--Soviet Union.
Poland--Defenses.
Poland--Foreign relations--Soviet Union
Poland--History--Occupation, 1939-1945
Soviet Union--Foreign relations--Germany.
Soviet Union--Foreign relations--Poland.
World War, 1939-1945--Campaigns--Poland.
Princeton subject headings: