Columbia subject headings:
Basilicas--Italy--Rome.
Catacombs--Italy--Rome.
Christian antiquities--Italy--Rome.
Rome (Italy)--Antiquities.
Harvard subject headings:
Basilicas--Italy--Rome--Guidebooks.
Catacombs--Italy--Rome--Guidebooks.
Christian antiquities--Italy--Rome--Guidebooks.
Rome (Italy)--Antiquities--Guidebooks.
Rome (Italy)--Guidebooks.
Princeton subject headings:
Basilicas--Italy--Rome.
Catacombs--Italy--Rome.
Christian antiquities--Italy--Rome.
Rome (Italy)--Antiquities.