Columbia subject headings:
Harvard subject headings:
Cities and towns--Italy--Pictorial works.
Lombardy (Italy)--Pictorial works.
Plazas--Italy--Lombardy.
Princeton subject headings:
Architecture--Italy--Lombardy.
Cities and towns--Italy--Lombardy--Pictorial works.
Lombardy (Italy)--Pictorial works.
Plazas--Italy--Lombardy.