Columbia subject headings:
Plazas--Conservation and restoration--Europe.
Plazas--Design and construction.
Plazas--Europe.
Harvard subject headings:
Plazas--Conservation and restoration--Europe.
Plazas--Design and construction.
Plazas--Europe.
Princeton subject headings:
Plazas--Conservation and restoration--Europe.
Plazas--Design and construction.
Plazas--Europe.