Columbia subject headings:
Harvard subject headings:
Libraries--Europe--History--400-1400--Congresses.
Scriptoria--Europe--History--Congresses.
Princeton subject headings:
Books--Europe--History--1450-1600--Congresses.
Books--Europe--History--400-1450--Congresses.
Libraries--Europe--History--To 1500--Congresses.
Scriptoria--Europe--History--To 1500--Congresses.