Columbia subject headings:
City planning--Italy--Perugia--History.
Perugia (Italy)--History.
Porta Santa Susanna (Perugia, Italy)
Harvard subject headings:
City planning--Italy--Perugia--History.
Perugia (Italy)--History.
Porta Santa Susanna (Perugia, Italy)
Princeton subject headings:
City planning--Italy--Perugia--History.
Perugia (Italy)--History.
Porta Santa Susanna (Perugia, Italy)