Columbia subject headings:
Mosaics--Conservation and restoration--Congresses.
Mosaics--Italy--Congresses.
Harvard subject headings:
Mosaics, Italian--Italy--Congresses.
Mosaics, Roman--Italy--Congresses.
Mosaics--Conservation and restoration--Italy--Congresses.
Princeton subject headings:
Mosaics--Conservation and restoration--Congresses.
Mosaics--Italy--Congresses.