Columbia subject headings:
Catholic Church--Relations--Eastern churches.
Catholic Church--Relations--Orthodox Eastern Church.
Eastern churches--Doctrines.
Orthodox Eastern Church--Doctrines.
Spirituality--Eastern churches--Congresses.
Spirituality--Orthodox Eastern Church--Congresses.
Harvard subject headings:
Catholic Church--Byzantine rite--Doctrines--History--Congresses.
Orthodox Eastern Church--Doctrines--History--Congresses.
Spirituality--Catholic Church--History of doctrines--Congresses.
Spirituality--Orthodox Eastern Church--History of doctrines--Congresses.
Princeton subject headings:
Catholic Church--Relations--Eastern churches.
Catholic Church--Relations--Orthodox Eastern Church.
Eastern churches--Doctrines.
Orthodox Eastern Church--Doctrines.
Spirituality--Eastern churches--Congresses.
Spirituality--Orthodox Eastern Church--Congresses.