Columbia subject headings:
Harvard subject headings:
Germany--Foreign relations--Poland.
Germany--Politics and government--1789-1900.
Germany--Politics and government--1918-1933
Germany--Politics and government--1933-1945.
Mazury (Poland : Region)--Politics and government.
Poland--Foreign relations--Germany
Prussia, East (Poland and Russia)--Politics and government.
Warmia (Poland)--Politics and government.
Princeton subject headings:
Mazury (Poland : Region)--History.
Warmia (Poland)--History.