Ritual of the Order of Saint Augustine, 2nd ed.
Cf. le no. 4236. 'The earliest manuscript, the Codex Reginensis, Bibl. Apost. Vaticana, Ms Reginenses Latini no. 1806 (s. XIII-XIV), 47ff. was examined and transcribed by Pancratius C. Langeveld OSA in 1960': 17.