P. Colletta, T. De Angelis, and F. Delle Donne, Eds., The Kingdom of Sicily during the Norman and Swabian age: forms and organization of culture and politics, vol. 6. SHARE Books, 2021. Accessed: Oct. 09, 2026. Available: https://www.fedoabooks.unina.it/index.php/fedoapress/catalog/book/239