Columbia subject headings:
Europe--History--392-814--Congresses.
Europe--History--To 476--Congresses.
Spain--History--To 711--Congresses.
Harvard subject headings:
Civilization, Ancient--Congresses
Civilization, Medieval--Congresses
Europe--History--392-814--Congresses.
Europe--History--To 476--Congresses.
Spain--History--To 711--Congresses.
Princeton subject headings:
Europe--History--392-814--Congresses.
Europe--History--To 476--Congresses.
Spain--History--To 711--Congresses.