Columbia subject headings:
Harvard subject headings:
Christian pilgrims and pilgrimages--Italy--Tiber River Valley--Congresses.
Pilgrims and pilgrimages--Italy--Tiber River Region--History--To 1500--Congresses.
Roads--Italy--Tiber River Region--History--To 1500--Congresses.
Tiber River Valley (Italy)--History--Congresses.
Travelers--Italy--Tiber River Valley--Congresses.
Princeton subject headings:
Christian pilgrims and pilgrimages--Italy--Tiber River Valley--Congresses.
Tiber River Valley (Italy)--History--Congresses.
Travelers--Italy--Tiber River Valley--Congresses.