Robert. Saint and Hero: Andreas and Medieval Doctrine. Lewisburg: Bucknell University Press, 1990. Collins, Paul. The Birth of the West: Rome, Germany, France, and the Creation of Europe in the Tenth Century. New York: PublicAffairs, 2013. Filotas, Bernadette. Pagan Survivals, Superstitions, and Popular Cultures in Early Medieval Pastoral Literature. Toronto: Pontifical Institute of Mediaeval Studies, 2005. Fowler-Magerl, Linda. Clavis Canonum: Selected Canon Law Collections Before 1140. Hanover: Hahnsche, 2005. Korfmacher, W. C. "Atto of Vercelli." In New Catholic Encyclopedia. Vol. 1. New York: McGraw-Hill, 1967. Petry, Ray C, ed. No Uncertain Sound: Sermons that Shaped the Pulpit Tradition. Philadelphia: Westminster Press, 1948. Valtorta, Benedetta. Clavis Scriptorum Latinorum Medii Aevi. Auctores Italiae (700-1000). Florence: SISMEL - Edizioni del Galluzzo, 2006. Wemple, Suzanne F. “The Canonical Resources of Atto of Vercelli (926-960).” Traditio 26 (1970): 335-350. Willhauck, George Alan. “The Letters of Atto, Bishop of Vercelli: Text, Translation, and Commentary.” Ph. D Dissertation, Tufts University, 1984. Zeigler, A.K. “Medieval Literature.” In New Catholic Encyclopedia. Vol. 9. New York: McGraw-Hill, 1967. 880s births Year of birth uncertain 961 deaths Bishops of Vercelli 10th-century Italian bishops 10th-century Latin writers 10th-century Italian writers 10th-century jurists