Columbia subject headings:
Excavations (Archaeology)--Italy--Tronto River Valley--Congresses.
Tronto River Valley (Italy)--Antiquities--Congresses.
Harvard subject headings:
Excavations (Archaeology)--Italy--Tronto River Valley--Congresses.
Tronto River Valley (Italy)--Antiquities--Congresses.
Princeton subject headings:
Excavations (Archaeology)--Italy--Tronto River Valley--Congresses.
Tronto River Valley (Italy)--Antiquities--Congresses.