Columbia subject headings:
Harvard subject headings:
Christianity--History of doctrines--Early church, ca. 30-600.
Council of Constantinople (2nd : 553 : Constantinople)
Councils and synods, Ecumenical.
Gnosticism
Origen
Princeton subject headings:
Church history--Primitive and early church, ca. 30-600.
Council of Constantinople (2nd : 553).
Origen.