Columbia subject headings:
Harvard subject headings:
Architecture and society--Italy--Siena.
Architecture, Domestic--Italy--Siena.
Architecture, Medieval--Italy--Siena.
Architecture--Italy--Siena.
Siena (Italy)--Buildings, structures, etc.
Princeton subject headings:
Architecture, Medieval--Italy--Siena.
Public architecture--Italy--Siena.
Siena (Italy)--Buildings, structures, etc.