Columbia subject headings:
Harvard subject headings:
Civilization, Classical--History.
Monotheism--Rome--History.
Rome--Civilization--History--Religious aspects.
Princeton subject headings:
Christianity and culture--History--Early church, ca. 30-600--Congresses.
Christianity and other religions--Roman--Congresses.
Monotheism--Congresses.
Polytheism--Congresses.
Rome--Religion--Congresses.
Rome--Religious life and customs--Congresses.