Columbia subject headings:
Harvard subject headings:
Mural painting and decoration--Conservation and restoration--Italy--Bologna.
Mural painting and decoration--Conservation and restoration--Italy--Ferrara.
Stone painting--Conservation and restoration--Italy--Bologna.
Stone painting--Conservation and restoration--Italy--Ferrara.
Princeton subject headings:
Architecture--Italy--Bologna--Conservation and restoration--Congresses.
Architecture--Italy--Ferrara--Conservation and restoration--Congresses.
Art--Italy--Bologna--Conservation and restoration--Congresses.
Art--Italy--Ferrara--Conservation and restoration--Congresses.