Columbia subject headings:
Bishops--History.
Church history--Primitive and early church, ca. 30-600.
Church polity--History--Early church, ca. 30-600.
Communication--Religious aspects--Christianity--History--Early church, ca. 30-600.
Harvard subject headings:
Bishops--Correspondence.
Church history--3rd century.
Church history--Primitive and early church, ca. 30-600
Communication--Religious aspects--Christianity
Communication--Rome--Religious aspects--Christianity.
Conflict management--Rome--Religious aspects--Christianity.
Persecution--History--Early church, ca. 30-600
Princeton subject headings: