Columbia subject headings:
Todi (Italy)--History--Congresses.
Harvard subject headings:
Art, Italian--Italy--Todi--Congresses.
Art, Medieval--Italy--Todi--Congresses.
Todi (Italy)--History--Congresses.
Todi (Italy)--Social conditions--Congresses.
Princeton subject headings:
Todi (Italy)--Congresses.