Tolong jelaskan mengenai Sumber dari Sigrand

Gerberding, Richard A., The Rise of the Carolingians and the Liber Hisgtoriae Francorum, Oxford University Press, 1987

Claussen, M. A., The Reform of the Frankish Church: Chrodegang of Metz and the Regula Canonicorum in the Eighth Century, Cambridge University Press, 2004

Medieval Lands Project, Family of Enguerrand, Comte de Paris