Paris, Impression Photomécanique, Les Procédés Dorel, 1948, 1926, format in-8°, 22 x 15 cm, 45 pp, printed musical scores with interlinear texts. Pars Antiquior, Pars Recentior, Pars ad libitum. . Photomechanical imprint of a manuscript score and text.Bound in black cloth . With some traces of use but still a good copy. Rare liturgical songbook of the Cisterciensian monastic order.