Columbia subject headings:
Canon law--History--Sources.
Canon law--History.
Catholic Church--Liturgy--History.
Durand, Guillaume, approximately 1230-1296.
Harvard subject headings:
Canon law--History.
Catholic Church--Liturgy--History.
Durand, Guillaume, approximately 1230-1296.
Princeton subject headings:
Canon law--History--Sources.
Durand, Guillaume, approximately 1230-1296.