Columbia subject headings:
Castles--Italy--Lombardy--Guidebooks.
Lombardy (Italy)--Guidebooks.
Harvard subject headings:
Castles--Italy--Lombardy--Guidebooks.
Castles--Italy--Lombardy--History.
Castles--Italy--Lombardy--Pictorial works.
Lombardy (Italy)--Guidebooks.
Princeton subject headings:
Castles--Italy--Lombardy--History.
Castles--Italy--Lombardy--Pictorial works.