Columbia subject headings:
Catholic Church--Doctrines--History--To 1500.
Marriage (Canon law)--History--To 1500.
Papacy--History--To 1500.
Harvard subject headings:
Catholic Church--Doctrines--History--To 1500.
Marriage (Canon law)--History--To 1500.
Papacy--History--To 1500.
Princeton subject headings: