December 20, 1928 Divini Cultus On Divine Worship “Published by Pope Pius XI 20 December 1928 Pius, Servant of the Servants of God, For Everlasting Memory Since the Church has received from...” Pope Pius XI
November 22, 1903 Tra Le Sollecitudini Instruction on Sacred Music “Motu Proprio promulgated by Pope Pius X on November 22, 1903 I. General Principles II. The different kinds of Sacred Music III. The Liturgical Text IV....” Pope Pius X
Religiosorum Institutio Instruction on the Careful Selection And Training Of Candidates For The States Of Perfection And Sacred Orders