The Tractatus de successivis : attributed to William Ockam / edited with a study on the life and works of Ockham by Philotheus Boehner O.T.M. - Ockham, William, m. c. 1349. Opere spurie e dubbie. (OLS)http://pul/name/7991 (The Franciscan Institute St. Bonaventure, 1944)