Columbia subject headings:
Cities and towns--Baltic Sea Region--History--Congresses.
Prussia, East (Poland and Russia)--History, Local--Congresses.
Prussia, West (Poland)--History, Local--Congresses.
Harvard subject headings:
Cities and towns--Baltic Sea Region--History--Congresses.
Prussia, East (Poland and Russia)--History, Local--Congresses.
Prussia, West (Poland)--History, Local--Congresses.
Princeton subject headings:
Cities and towns--Baltic Sea Region--History--Congresses.
Prussia, East (Poland and Russia)--History, Local--Congresses.
Prussia, West (Poland)--History, Local--Congresses.