Columbia subject headings:
Basilicas--Conservation and restoration--Vatican City.
Excavations (Archaeology)--Vatican City.
Tombs--Vatican City.
Vatican City--Antiquities.
Harvard subject headings:
Basilica di San Pietro in Vaticano.
Christian antiquities--Rome.
Excavations (Archaeology)--Rome.
Excavations (Archaeology)--Vatican City.
Rome (Italy)--Antiquities.
Princeton subject headings: