Breviarium Gothicum, edited by A. Lorenzana. Madrid, 1775. See Migne, P. L., 86.

Britt, M., Hymns of the Breviary and Missal. New York, 1922, 1948.

Buchanan, E. S., An early Latin song-book. New York, 1930. 13th C. Ms.

Burgess, H., Select metrical hymns and homilies of Ephrem Syrus. London, 1855.

Chambers, J. D., Divine worship in England in the 13th and 14th, contrasted with and adapted to that in the 19th C. London, 1877.

Chatfield, A. W., Songs and hymns of the earliest Greek Christian poets. London, 1876.

Dowden, J., Church year and kalendar. Cambridge, 1910.

Duchesne, L., Origines du culte chrétien. Translation Christian worship: origin and evolution from the 3rd French edition by M. L. McClure. London, 1904.

Durandus, Gulielmus, Rationale divinorum officiorum (1286). Lugduni, 1612.

Fisher, A. H., Cathedral church of Hereford. London, 1898.