Columbia subject headings:
Bulls, Papal.
Church history--Middle Ages, 600-1500--Sources.
Letters, Papal.
Rescripts, Papal.
Harvard subject headings:
Bulls, Papal.
Church history--Middle Ages, 600-1500--Sources.
Letters, Papal.
Rescripts, Papal.
Princeton subject headings:
Canon law--Papal documents.
Catholic Church--History--Sources.