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-referens (17:e uppl.)Catholic Church. Pope (1922-1939 : Pius XI) och Pope Pius XI. Why a Retreat?: "Mens Nostra," the Encyclical of Pope Pius XI on Laymen's Retreats. New York: Paulist Press.
MLA-referens (8:e uppl.)Catholic Church. Pope (1922-1939 : Pius XI) och Pope Pius XI. Why a Retreat?: "Mens Nostra," the Encyclical of Pope Pius XI on Laymen's Retreats. Paulist Press.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.