Columbia subject headings:
Harvard subject headings:
Cities and towns--Europe, Central--History--Congresses.
Cities and towns--Europe, Western--History--Congresses.
Mountains--Economic aspects--Congresses.
Mountains--Social aspects--Congresses.
Princeton subject headings:
Cities and towns--Europe, Central--History--Congresses.
Cities and towns--Europe, Western--History--Congresses.
Mountains--Economic aspects--Congresses.
Mountains--Social aspects--Congresses.