Columbia subject headings:
Architecture, Renaissance--Vatican City.
Architecture--Vatican City.
Basilica di San Pietro in Vaticano.
Piazza San Pietro (Vatican City)
Vatican City--Buildings, structures, etc.
Harvard subject headings:
Basilica di San Pietro in Vaticano--Guidebooks.
Christian art and symbolism--Italy--Rome--Guidebooks.
Vatican City--Buildings, structures, etc--Guidebooks.
Princeton subject headings:
Basilica di San Pietro in Vaticano--Guidebooks.
Christian art and symbolism--Italy--Rome--Guidebooks.
Vatican City--Buildings, structures, etc--Guidebooks.