Catholic Church. Pope (1922-1939 : Pius XI) & Pius XI, P. Why a retreat?: "Mens nostra," the encyclical of Pope Pius XI on Laymen's retreats. Paulist Press.
Chicago-viite (17. p.)Catholic Church. Pope (1922-1939 : Pius XI) ja Pope Pius XI. Why a Retreat?: "Mens Nostra," the Encyclical of Pope Pius XI on Laymen's Retreats. New York: Paulist Press.
MLA-viite (8. p.)Catholic Church. Pope (1922-1939 : Pius XI) ja Pope Pius XI. Why a Retreat?: "Mens Nostra," the Encyclical of Pope Pius XI on Laymen's Retreats. Paulist Press.
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