Columbia subject headings:
Harvard subject headings:
Architecture, Roman--Europe--History--Congresses.
Architecture, Roman--Italy--History--Congresses.
Architecture, Roman--Rome--History--Congresses.
Europe--Buildings, structures, etc.--Congresses.
Italy--Buildings, structures, etc.--Congresses.
Rome--Buildings, structures, etc.--Congresses.
Princeton subject headings:
Architecture, Roman--Gaul.
Architecture, Roman--Germany.
Architecture, Roman--Switzerland.
Architecture, Roman.