Columbia subject headings:
Civilization, Medieval--Congresses.
Europe--Boundaries--Congresses.
Europe--Ethnic relations--Congresses.
Europe--Historical geography--Congresses.
Harvard subject headings:
Civilization, Medieval--Congresses
Europe--Boundaries--Congresses.
Europe--Ethnic relations--Congresses.
Europe--Historical geography--Congresses.
Princeton subject headings:
Civilization, Medieval--Congresses.
Europe--Boundaries--Congresses.
Europe--Ethnic relations--Congresses.
Europe--Historical geography--Congresses.