Columbia subject headings:
Bible and law.
Canon law--History--To 1500.
Church and state--Holy Roman Empire.
Church history--11th century.
Church history--12th century.
Gratian, active 12th century. Decretum.
Investiture (Canon law)
Investiture--History--To 1500.
Law, Medieval--History.
Law--Methodology--History--To 1500.
Polemics--History.
Harvard subject headings:
Princeton subject headings:
Bible and law.
Canon law--History.
Polemics.