Ugo wa Rouen
Gesta Hugonis archiepiscopi Rotomagensis in the Gesta (sanctorum patrum) Fontanellensis coenobii (dated between about 833 and 840), ed. Samuel Löwenfeld. Gesta Abbatum Fontanellensium. MGH Scriptores rer. Germ. 28. Hanover, 1886 (reprinted 1980). 26-8; ed. F. Lohier and J. Laporte. Gesta sanctorum patrum Fontanellensis coenobii. Société de l'histoire de Normandie. Rouen, 1936. 37–43.