Columbia subject headings:
Germany--Boundaries--Poland--History--Sources.
Poland--Boundaries--Germany--History--Sources.
Poland--History--Occupation, 1939-1945.
Poland--Politics and government--1918-1945.
Western and Northern Territories (Poland)--History--Sources.
Western and Northern Territories (Poland)--History.
Harvard subject headings:
Princeton subject headings:
Western and Northern Territories (Poland)--History--20th century--Sources.