Columbia subject headings:
Architecture, Medieval--Vatican City.
Architecture--Vatican City.
Rione Borgo (Vatican City)--History.
Vatican City--Buildings, structures, etc.
Vatican City--History.
Harvard subject headings:
Architecture, Medieval--Vatican City.
Architecture--Vatican City.
City planning--Vatican City--History.
Rione Borgo (Vatican City)--History.
Urbanization--Vatican City--History.
Vatican City--Buildings, structures, etc.
Vatican City--Buildings, structures, etc.--History.
Vatican City--History.
Princeton subject headings:
Architecture, Medieval--Vatican City.
Architecture--Vatican City.
Rione Borgo (Vatican City)--History.
Vatican City--Buildings, structures, etc.
Vatican City--History.