FIRTH, Francis (ed.):Robertus Flamesburiensis, Robert of Flamborough. Liber poenitentialis. A critical edition with introduction and notes by J.J. Francis Firth C.S.B., Pontifical Institute of Mediaeval Studies, 1971.
FIRTH, Francis:The ‘Poenitentiale' of Robert of Flamborough: An Early Handbook for the Confessor in its Manuscript Tradition, Traditio, Vol.16, pp.541-556.