Columbia subject headings:
Church history--Primitive and early church, ca. 30-600.
Popes--Primacy--History--Early church, ca. 30-600.
Harvard subject headings:
Popes--Primacy
Princeton subject headings:
Church history--Primitive and early church, ca. 30-600.
Popes--Primacy--History--Early church, ca. 30-600.