Leupen, P. “V.D. Van Aalst, K.N. Ciggaar, Byzantium and the Low Countries in Het Tenth Century. Aspects of Art and History in the Ottonian Era”. BMGN - Low Countries Historical Review, vol. 103, no. 1, Jan. 1988, pp. 62-63, doi:10.18352/bmgn-lchr.2902.