Columbia subject headings:
Harvard subject headings:
Civilization, Medieval--Congresses
Diplomacy--History--To 1500--Congresses.
Negotiation--History--To 1500--Congresses.
Spain--History--711-1516--Congresses.
Princeton subject headings:
Civilization, Medieval--Congresses.
Diplomacy--History--To 1500--Congresses.
Negotiation--History--To 1500--Congresses.
Spain--History--711-1516--Congresses.