Columbia subject headings:
Harvard subject headings:
Architecture in art--Congresses.
Architecture, Medieval--Italy--Rome--Congresses.
Rome (Italy)--Buildings, structures, etc.--Congresses.
Rome (Italy)--Church history--Congresses.
Princeton subject headings:
Architecture, Domestic--Italy--Rome.
Architecture, Medieval--Italy--Rome.
Cardinals--Dwellings--Italy--Rome.
Popes--Dwellings--Italy--Rome.
Rome (Italy)--Buildings, structures, etc.