Columbia subject headings:
Church history--Middle Ages, 600-1500.
Church history--Primitive and early church, ca. 30-600.
Harvard subject headings:
Church history--Middle Ages, 600-1500
Church history--Primitive and early church, ca. 30-600
Princeton subject headings:
Church history--Middle Ages, 600-1500.
Church history--Primitive and early church, ca. 30-600.