Columbia subject headings:
Harvard subject headings:
Bŭlgarska pravoslavna t︠s︡ŭrkva--Relations.
Orthodoxos Ekklēsia tēs Hellados--Relations.
Princeton subject headings:
Bŭlgarska pravoslavna t︠s︡ŭrkva--History.
Bŭlgarska pravoslavna t︠s︡ŭrkva--Relations--Constantinople (Ecumenical patriarchate)
Constantinople (Ecumenical patriarchate)--Relations--Bŭlgarska pravoslavna t︠s︡ŭrkva.