Dom René de Sainte-Beuve as transcribed by Crochu, corrected according to Crochu's restitution of O crux benedicta (http://gregofacsimil.free.fr/01-Restitution/Repons/Repons-en-pdf/50-In-Stae-Crucis-Inventione/09-O-crux-benedicta-quae-sola.pdf) and neumes from said R/ (cf. source)