Mens in nequitia ponens / O dira natio peior

Bibliography

Harrison, Frank Llewellyn, Peter M Lefferts, and Ernest Sanders (eds.) 1986. English Music for Mass and Offices (II) and Music for Other Ceremonies. Polyphonic Music of the Fourteenth Century.  Monaco: Éditions de L'Oiseau Lyre. pp. 153ff. (no. 55).