Columbia subject headings:
Architecture--Conservation and restoration--Europe.
Cities and towns--Conservation and restoration--Europe.
Historic buildings--Conservation and restoration--Europe.
Historic districts--Conservation and restoration--Europe.
Premio Gubbio.
Harvard subject headings:
Architecture--Conservation and restoration--Europe.
Cities and towns--Conservation and restoration--Europe.
Historic buildings--Conservation and restoration--Europe.
Historic districts--Conservation and restoration--Europe.
Premio Gubbio.
Princeton subject headings: