Columbia subject headings:
Italy--Antiquities--Guidebooks.
Rome (Italy)--Antiquities--Guidebooks.
Underground areas--Italy--Rome--Guidebooks.
Harvard subject headings:
Catacombs--Italy--Rome--Guidebooks.
Rome (Italy)--Antiquities--Guidebooks.
Underground areas--Italy--Rome--Guidebooks.
Princeton subject headings:
Historic buildings--Italy--Rome.
Historic sites--Italy--Rome.
Rome (Italy)--Antiquities.
Rome (Italy)--Description and travel.
Rome (Italy)--Pictorial works.
Underground areas--Italy--Rome.