Columbia subject headings:
Civilization, Medieval--Congresses.
Space perception--Europe--Congresses.
Spatial behavior--Europe--Congresses.
Harvard subject headings:
Civilization, Medieval--Congresses
Space perception--Europe--Congresses.
Spatial behavior--Europe--Congresses.
Princeton subject headings:
Civilization, Medieval--Congresses.
Europe--History--476-1492--Congresses.
Social ecology--Europe--History--Congresses.