Columbia subject headings:
Byzantine Empire--Church history--Congresses.
Constantinople (Ecumenical patriarchate)--History--Sources--Congresses.
Harvard subject headings:
Byzantine Empire--Church history--Congresses.
Constantinople (Ecumenical patriarchate)--History--Sources--Congresses.
Constantinople (Ecumenical patriarchate)--History.
Constantinople (Ecumenical patriarchate)--Sources.
Princeton subject headings:
Constantinople (Ecumenical patriarchate)--History--Sources--Congresses.
Orthodox Eastern Church--History--Sources--Congresses.