Paul VI, P. Apostolic letter of His Holiness Pope Paul VI to Cardinal Maurice Roy, president of the Council of the Laity and of the Pontifical Commission Justice and Peace, on the occasion of the eightieth anniversary of the encyclical Rerum novarum. [publisher not identified].

Paul VI, Pope. Apostolic Letter of His Holiness Pope Paul VI to Cardinal Maurice Roy, President of the Council of the Laity and of the Pontifical Commission Justice and Peace, on the Occasion of the Eightieth Anniversary of the Encyclical Rerum Novarum. [Place of publication not identified]: [publisher not identified].

Paul VI, Pope. Apostolic Letter of His Holiness Pope Paul VI to Cardinal Maurice Roy, President of the Council of the Laity and of the Pontifical Commission Justice and Peace, on the Occasion of the Eightieth Anniversary of the Encyclical Rerum Novarum. [publisher not identified].