Columbia subject headings:
Harvard subject headings:
Cities and towns, Medieval--Congresses
Civilization, Medieval--Congresses
Communication and culture--Europe--History--To 1500--Congresses.
Communication--Europe--History--To 1500--Congresses.
Princeton subject headings:
Cities and towns, Medieval--Congresses.
Civilization, Medieval--Congresses.
Communication and culture--History--To 1500--Congresses.