J. M. González del Valle, «CHARLES H. O’BRIEN, Ideas of religious toleration at the time of Joseph II. A study of the enlightment among catholics in Austria, en “Transactions of the American Philosophical Society”, 1 vol. de 84 págs., de 24 X 30 cms., Ed. The American Philosophical Society, Filadelfia, 1969», Ius Canonicum, vol. 11, n.º 22, pp. 504-505, nov. 1971.