Powell, James M., Innocent III: Vicar of Christ or Lord of the World? - Boston: Heath, [1963] - xv, 74 p. : aantn., lit. opg. ; 24 cm. - Problems in European civilization . Ed. with an introd. Subjects--Topical Terms: Church history--Middle Ages, 600-1500. LC Class. No.: BX 1236 / .P6 1963