Columbia subject headings:
Church architecture--Italy--Siena.
Duomo di Siena.
Siena (Italy)--Buildings, structures, etc.
Harvard subject headings:
Archaeology, Medieval--Italy--Siena.
Architecture, Medieval--Italy--Siena.
Building--Italy--Siena--History--To 1500.
Church architecture--Italy--Siena.
Duomo di Siena.
Siena (Italy)--Buildings, structures, etc.
Princeton subject headings:
Church architecture--Italy--Siena.
Duomo di Siena.
Siena (Italy)--Buildings, structures, etc.