Columbia subject headings:
Harvard subject headings:
Adriatic Coast (Italy)--History.
Architecture--Italy--Adriatic Coast--History.
Architecture--Italy--Po River Plain--History.
Art--Italy--Adriatic Coast--History.
Art--Italy--Po River Plain--History.
Po River Plain (Italy)--History.
Roads--Italy--Adriatic Coast--History.
Roads--Italy--Po River Plain--History.
Princeton subject headings:
Adriatic Coast (Italy)--Civilization.
Art, Italian--Italy--Adriatic Coast.
Art, Italian--Italy--Po River Valley.
Christian pilgrims and pilgrimages--Italy--Adriatic Coast.
Christian pilgrims and pilgrimages--Italy--Po River Valley.
Po River Valley (Italy)--Civilization.