Columbia subject headings:
Catholic Church--Relations--Orthodox Eastern Church--Congresses.
Kievan Rus--Church history--Congresses.
Millennium of Christianity in Kievan Rus, 988-1988--Congresses.
Orthodox Eastern Church--Relations--Catholic Church--Congresses.
Russkai︠a︡ pravoslavnai︠a︡ t︠s︡erkovʹ--History--Congresses.
Harvard subject headings:
Christianity--Russia--History--Congresses.
Russia--Church history--Congresses.
Princeton subject headings:
Catholic Church--Relations--Orthodox Eastern Church--Congresses.
Kievan Rus--Church history--Congresses.
Millennium of Christianity in Kievan Rus, 988-1988--Congresses.
Orthodox Eastern Church--Relations--Catholic Church--Congresses.
Russkai︠a︡ pravoslavnai︠a︡ t︠s︡erkovʹ--History--Congresses.