Columbia subject headings:
City planning--Italy--Viterbo.
Historic districts--Italy--Viterbo.
Urban renewal--Italy--Viterbo--Planning.
Harvard subject headings:
City planning--Italy--Viterbo.
Historic districts--Italy--Viterbo.
Urban renewal--Italy--Viterbo--Planning.
Princeton subject headings:
City planning--Italy--Viterbo.
Historic districts--Italy--Viterbo.
Urban renewal--Italy--Viterbo--Planning.