Columbia subject headings:
Local laws--Italy--Viterbo.
Ordinances, Municipal--Italy--Viterbo--13th century.
Viterbo (Italy)--History--Sources.
Harvard subject headings:
Law--Italy--Viterbo--History--Sources.
Local laws--Italy--Viterbo.
Middle Ages--Sources
Ordinances, Municipal--Italy--Viterbo--13th cent.
Ordinances, Municipal--Italy--Viterbo.
Thirteenth century--History--Sources.
Viterbo (Italy)--History--Sources.
Princeton subject headings:
Viterbo (Italy)--History--Sources.