Columbia subject headings:
Harvard subject headings:
Architecture, Romanesque--Italy--Marche--Congresses.
Architecture, Romanesque--Italy--Umbria--Congresses.
Art, Romanesque--Italy--Marche--Congresses.
Art, Romanesque--Italy--Umbria--Congresses.
Princeton subject headings:
Art, Romanesque--Italy--Marche--Congresses.
Art, Romanesque--Italy--Umbria--Congresses.