Columbia subject headings:
Plazas in art--Congresses.
Plazas--Congresses.
Public art--Congresses.
Harvard subject headings:
Architecture and society--Congresses
City planning--Congresses
Plazas in art--Congresses.
Plazas--Congresses.
Public art--Congresses.
Princeton subject headings:
Plazas in art--Congresses.
Plazas--Congresses.
Public art--Congresses.