Previté Orton, C. W. «Italy and Provence, 900—950.»The English Historical Review, Vol. 32, No. 127. (Jul., 1917), pp 335—347.
Reuter, Timothy (trans.) The Annals of Fulda. (Manchester Medieval series, Ninth-Century Histories, Volume II.) Manchester: Manchester University Press, 1992.
Reuter, Timothy. Germany in the Early Middle Ages 800—1056. New York: Longman, 1991.
MacLean, Simon. Kingship and Politics in the Late Ninth Century: Charles the Fat and the end of the Carolingian Empire. Cambridge University Press: 2003.
Wickham, Chris. Early Medieval Italy: Central Power and Local Society 400—1000. MacMillan Press: 1981.
Tabacco, Giovanni. The Struggle for Power in Medieval Italy: Structures and Political Rule. (Cambridge Medieval Textbooks.) Cambridge: Cambridge University Press, 1989.
Llewellyn, Peter. Rome in the Dark Ages. London: Faber and Faber, 1970. ISBN 0-571-08972-0.