Columbia subject headings:
Germany--Relations--Poland--Congresses.
Poland--Relations--Germany--Congresses.
Pomerania (Poland and Germany)--History--Congresses.
Silesia--History--Congresses.
Harvard subject headings:
Germany--Relations--Poland--Congresses.
Poland--Relations--Germany--Congresses
Pomerania (Poland and Germany)--History--Congresses.
Silesia--History--Congresses.
Princeton subject headings: