Columbia subject headings:
Architecture--Italy--Piacenza--Congresses.
City planning--Environmental aspects--Italy--Piacenza--Congresses.
City planning--Study and teaching--Italy--Piacenza--Congresses.
Harvard subject headings:
Architecture--Italy--Piacenza--Congresses.
City planning--Environmental aspects--Italy--Piacenza--Congresses.
City planning--Study and teaching--Italy--Piacenza--Congresses.
Princeton subject headings:
Architecture--Italy--Piacenza--Congresses.
City planning--Environmental aspects--Italy--Piacenza--Congresses.
City planning--Study and teaching--Italy--Piacenza--Congresses.