Hourlier believed that lat. 12601 originated at Cluny and was later used in the Picard monastery of St. Taurin l'Echelle. Recently Manuel Pedro Ferreira has called attention to the presence in the source of two different types of neumes--both French and Laon (Lorraine)--that appear to be roughly contemporaneous, suggesting that the manuscript originated in a place in which the two coexisted. He believes that the manuscript cannot have originated at Cluny itself because of the manuscript's "notational, liturgical, paleographical and artistic oddities." All chants not found in CAO are assigned an arbitrary number beginning with "clu". The manuscript contains no differentiae, with only one exception (assigned to the single antiphon written in staff notation, on f. 78r, for Taurinus, which has been given an arbitrary number).
- Leroquais, Victor. Les Breviaires: manuscrits des Bibliotheques publiques de France, 3: 226-28. Paris; Macon: Protat Freres, 1934.
- Hourlier, Jacques. "Le Breviaire de Saint-Taurin: Un livre liturgique clunisien a l'usage de l'Echelle-Saint-Aurin (Paris, B. N. lat. 12601)." Etudes gregoriennes 3 (1959): 163-73.
- Lamothe, Donat R. and Constantine, Cyprian G. eds. Matins at Cluny for the Feast of Saint Peter's Chains. London: Plainsong and Mediaeval Music Society, 1986.
- Steiner, Ruth. "Marian Antiphons at Cluny and Lewes." In Music in the Medieval English Liturgy: Plainsong and Mediaeval Music Society Centennial Essays, ed. Susan Rankin and David Hiley, 175-204. Oxford: Clarendon Press, 1993.
- Ferreira, Manuel P. "Music at Cluny: The Tradition of Gregorian Chant for the Proper of the Mass. Melodic Variants and Microtonal Nuances." Ph.D. diss., Princeton University, 1997. (F-Pn lat. 12601 is described on pp. 45-48.)