^Settipani, Christian (1993). La Préhistoire des Capétiens (Nouvelle histoire généalogique de l'auguste maison de France, 1). Villeneuve-d'Ascq: Ed. Patrick van Kerrebrouck. p. 229. ISBN978-2-95015-093-6.
Sources
Dunbabin, Jean (2005). France in the Making 843-1180. Oxford University Press.
Riché, Pierre (1983). The Carolingians: A Family who Forged Europe. Translated by Allen, Michael Idomir. University of Pennsylvania Press.