Columbia subject headings:
Harvard subject headings:
Cities and towns--Germany--Prussia--History--Congresses.
Cities and towns--Poland--History--Congresses.
Poland--Relations--Germany--Prussia--Congresses.
Prussia (Germany)--Relations--Poland--Congresses.
Princeton subject headings:
Cities and towns--Germany--Prussia--History--Congresses.
Cities and towns--Poland--History--Congresses.
Poland--Relations--Germany--Prussia--Congresses.
Prussia (Germany)--Relations--Poland--Congresses.