Columbia subject headings:
Christians--Italy--Sicily--History--Congresses.
Excavations (Archaeology)--Italy--Sicily--Congresses.
Sicily (Italy)--Antiquities, Roman--Congresses.
Sicily (Italy)--History--To 800--Congresses.
Harvard subject headings:
Christian antiquities--Italy--Iblei Mountains--Congresses.
Iblei Mountains (Italy)--Antiquities--Congresses.
Iblei Mountains (Italy)--Church history--Congresses.
Princeton subject headings: