Columbia subject headings:
Bridges--Italy--Rome (Province)--History.
Fortification--Italy--Rome (Province)--History.
Rome (Italy : Province)--Buildings, structures, etc.
Harvard subject headings:
Bridges--Italy--Rome (Province)--History.
Fortification--Italy--Rome (Province)--History.
Rome (Italy : Province)--Buildings, structures, etc.
Princeton subject headings:
Bridges--Italy--Rome (Province).
Fortification--Italy--Rome (Province).
Rome (Italy : Province)--Buildings, structures, etc.