Rollo the Viking in Norse Warfare, pg. 15-16

Rollo and Ragnvald in History of the Norwegian People, pgs. 122, 130, 145-148

Ragnvald, Earl of More, in Sutherland and Caithness in Saga Time, pgs. 20, 22-24

Ragnvald and Rollo in Norges, Sveriges og Danmarks Historie for Middelskolen, pg. 11-13

Ragnvald and Rollo in The Gentleman's Magazine, Vol 5, New Series, pg. 41-42

Ragnvald and Rollo in Den Danske Erobring af England og Normandiet, pg. 140-141

Ragnvald, Rollo and William the Conqueror in Norge, Det Norska Folks Historie, pg. 32

Ragnvald and Rollo in Monumenta Orcadica, The Norsemen in the Orkneys, pg. 64

Ragnvald and Rollo in Maal og Minne, Norske Studier, pg. 104-106

Ragnvald and Rollo in Illustrerad Verldshistoria, pg. 200-202

Rollo in A Brief History of the Normans, pg. 58-62

Rollo, Ragnvald and William Longsword in Wilhelm der Eroberer, pg. 26-27

Rollo (Rollon) and Ragnvald in Histoire de Expeditions Maritimes des Normands, pgs. 329-330

Rollo, Duke of Normandy, in Historie des Peuples du Nord, pgs. 128, 293 and 294

Ragnvald and Rollo in Histoire des Expeditions Maritimes des Normands, pg. 52-54

Hrollager, Rollo, Ragnvald and William Long Sword in Memoires de la Societe D'Archeologie, Vol. VI, pg. 83-84

Ragnvald, Rollo and Hrollager in The Parshall Family A.D. 870-1913, pg. 45

Ragnvald, Rollo Duke of Normandy and Hrollager in The Battle Abbey Roll, Vol. 1, pg. 44

Rollo and William Long Sword in Guide Bleu Normandie, pg. 61-63

Sigurd, Ragnvald and Torf Einer in Heimskringla, pg. 218

Ragnvald, Hallad, Einer and Rollo in Undersogelse af Kongesagaens Fremvaext, pg. 87-89

Ragnvald and Rollo in Udsigt Over Den Norske Historie, pg. 91 and footnote

Ragnvald and Rollo in The Orkney Story, pg. 47