La Trobe University - Library: Medieval Music Database - Annual cycle of feasts of liturgical chant, liturgical polyphony and secular music of the late middle ages.

Medieval Music Database - Browse By Manuscript

London, British Library, Additional 57950 (olim Old Hall, Library of St. Edmund's College)
Modena, Biblioteca Estense e Universitaria, a. X.1.11 (Lat. 471; @olim* VI.H.15) - not catalogued here.
Oxford, Bodleian Library, University College 192
Trent, Castel del Buon Consiglio 90 - not catalogued here.
Trent, Castel de Buon Consiglio 93 - not catalogued here.