Columbia subject headings:
Harvard subject headings:
Catholic Church--Italy--Piacenza--History.
Church history--Middle Ages, 600-1500
Cities and towns--Italy--Piacenza.
Piacenza (Italy)--Church history--Middle Ages, 600-1500.
Saints--Cult--Italy--Piacenza.
Princeton subject headings:
Christian hagiography--Historiography.
Christian saints--Biography--History and criticism.
Christian saints--Cult--Italy--Piacenza--History.
Piacenza (Italy)--Church history.