Columbia subject headings:
Ravenna (Italy)--History.
Urbanization--Italy--Ravenna--History.
Harvard subject headings:
City planning--Italy--Ravenna--History.
Ravenna (Italy)--Buildings, structures, etc.
Ravenna (Italy)--History.
Urbanization--Italy--Ravenna--History.
Princeton subject headings:
Ravenna (Italy)--History.
Urbanization--Italy--Ravenna--History.