— Medieval Theories of the Just Price. Romanists, Canonists and Theologians in the twelfth and thirteen centuries, 1959
— Masters, Princes, and Merchants; the Social Views of Peter the Chanter & his Circle (Princeton: Princeton Univ. Press, 1970)
— The Scholastic Culture of the Middle Ages, 1000-1300 (Lexington: Heath, 1971)
— Universities in Politics; Case Studies from the Late Middle Ages and Early Modern period. Edited with Richard A. Goldthwaite (Baltimore:... (lire la suite...