Columbia subject headings:
Viterbo (Italy)--Church history--Sources.
Harvard subject headings:
Catholic Church--Italy--Viterbo--Clergy--History--Sources.
Catholic Church--Italy--Viterbo--Finance--History--Sources.
Viterbo (Italy)--Church history--Sources.
Viterbo (Italy)--History--Sources.
Wills--Italy--Viterbo--History--Sources.
Princeton subject headings:
Catholic Church--Italy--Viterbo--Clergy--History--Sources.
Catholic Church--Italy--Viterbo--Finance--History--Sources.
Viterbo (Italy)--Church history--Sources.
Viterbo (Italy)--History--Sources.
Wills--Italy--Viterbo--History--Sources.