Columbia subject headings:
City planning--Italy--Perugia.
City walls--Conservation and restoration--Italy--Perugia.
City walls--Italy--Perugia.
Perugia (Italy)--Buildings, structures, etc.
Harvard subject headings:
City planning--Italy--Perugia.
City walls--Conservation and restoration--Italy--Perugia.
City walls--Italy--Perugia.
Perugia (Italy)--Buildings, structures, etc.
Princeton subject headings:
City planning--Italy--Perugia.
City walls--Conservation and restoration--Italy--Perugia.
City walls--Italy--Perugia.
Perugia (Italy)--Buildings, structures, etc.