Tolong jelaskan mengenai Sumber dari Sancho VI William dari Gascony

Higounet, Charles. Bordeaux pendant le haut moyen âge. Bordeaux, 1963.

Lewis, Archibald R. The Development of Southern French and Catalan Society, 718–1050. University of Texas Press: Austin, 1965.

Zurita, Gerónimo. Anales de la Corona de Aragón I. Edited by Antonio Ubieto Arteta and Desamparados Pérez Soler. Valencia: 1967.