Columbia subject headings:
Harvard subject headings:
Civilization, Medieval--Congresses
Power (Social sciences)--History--To 500--Congresses.
Sounds--History--To 1500--Congresses.
Sounds--Political aspects--Congresses.
Sounds--Social aspects--Congresses.
Princeton subject headings:
History, Ancient--Congresses.
Other (Philosophy)--Social aspects--Congresses.
Power (Social sciences)--Congresses.
Speech and social status--Congresses.