Columbia subject headings:
Hymns, Greek--Bibliography.
Hymns, Greek--History and criticism--Bibliography.
Harvard subject headings:
Catholic Church--Byzantine rite, Greek--Hymns--History and criticism--Bibliography.
Catholic Church--Byzantine rite, Greek--Liturgy--Bibliography.
Church history--Middle Ages, 600-1500
Hymns, Greek--History and criticism--Bibliography.
Orthodox Eastern Church--Hymns--History and criticism--Bibliography.
Orthodox Eastern Church--Liturgy--Bibliography.
Princeton subject headings:
Hymns, Greek--Bibliography.
Hymns, Greek--History and criticism--Bibliography.