Columbia subject headings:
Cities and towns, Medieval--Congresses.
Cities and towns, Medieval--Germany--Congresses.
Civilization, Medieval--12th century--Congresses.
Harvard subject headings:
Cities and towns, Medieval--Congresses
Cities and towns, Medieval--Germany--Congresses.
Civilization, Medieval--12th century--Congresses.
Europe--Antiquities--Congresses.
Excavations (Archaeology)--Europe--Congresses
Excavations (Archaeology)--Germany--Congresses.
Germany--Antiquities--Congresses.
Princeton subject headings:
Civilization, Medieval--12th century--Congresses.