Arnulf, Bishop of Lisieux. The Letters of Arnulf of Lisieux. Edited by Frank Barlow. Camden Third Series 61. London: Royal Historical Society, 1939.
John X. "Epistola ad Heriveum archiepiscopum Rhemensem." In Flodoardi canonici Remensis opera omnia, edited by J.-P. Migne, cols. 27-29. Patrologia Latina 131. Paris: Garnier Fratres, 1879. What to do about converted and then relapsed Vikings.
Suger, Abbot of Saint-Denis. Sugerii abbatis S. Dionysii opuscula et epistolae. Edited by J.-P. Migne. Patrologia Latina 186. Paris: Garnier Fratres, s.d.