Columbia subject headings:
Basilica di San Pietro in Vaticano.
Christian antiquities--Italy--Rome.
Italy--Antiquities.
Peter, the Apostle, Saint--Tomb.
Rome (Italy)--Antiquities.
Harvard subject headings:
Basilica di San Pietro in Vaticano.
Peter, the Apostle, Saint.
Princeton subject headings:
Basilica di San Pietro in Vaticano.
Peter, the Apostle, Saint--Relics.
Peter, the Apostle, Saint--Tomb.