Christoph Flüeler,
founder and director
University of Fribourg
Cologny, Fondation Martin Bodmer, Cod. Bodmer 77, f. 57r – Guido Aretinus, Micrologus; Prologus in Antiphonarium; De ignoto cantu; Regulae rhythmicae
http://www.e-codices.ch/en/fmb/cb-0077/57r