1. Borders J. , ‘The Cathedral of Verona as a Musical Center in the Middle Ages: Its History, Manuscripts, and Liturgical Practice’, Ph.D. Diss. (University of Chicago, 1983), pp. 467–84
2. Barrett S. , ‘The Writing of Paris 1154’, unpublished M.Phil, diss. (Faculty of Music, Cambridge University, 1996), ch. 2