Columbia subject headings:
Architecture--Conservation and restoration--Congresses.
Cities and towns--Interpretive programs--Congresses.
City planning--History--20th century--Congresses.
Harvard subject headings:
Architecture, Modern--20th century--Congresses
Princeton subject headings:
Architecture--Conservation and restoration--Congresses.
Cities and towns--Interpretive programs--Congresses.
City planning--History--20th century--Congresses.