From two sermons delivered on their festival, the one
by St. Ennodius, the other passes under the name of St.
Ambrose, and was written soon after his time, perhaps by
St. Gaudentius of Brescia; also from Paulinus the deacon,
in his life of St. Ambrose. See Tillemont, t. 2, and Pinius
the Bollandist, t. 6, Julij, p. 503.