Columbia subject headings:
Germany--Foreign relations--1918---Congresses.
Germany--Foreign relations--Poland--Congresses.
Imperialism--Congresses.
Poland--Foreign relations--1918-1945--Congresses.
Poland--Foreign relations--Germany--Congresses.
Harvard subject headings:
Germany--Foreign relations--1918---Congresses.
Germany--Foreign relations--Poland--Congresses.
Imperialism--Congresses
Poland--Foreign relations--1918-1945--Congresses.
Poland--Foreign relations--Germany--Congresses.
Princeton subject headings: