Catholic Church. Pope (1958-1963 : John XXIII) & Gibbons, W. J. (1961). Mater et magistra: Encyclical letter of His Holiness Pope John XXIII: Christianity and social progress. Paulist Press.
Chicago-referens (17:e uppl.)Catholic Church. Pope (1958-1963 : John XXIII) och William J. Gibbons. Mater Et Magistra: Encyclical Letter of His Holiness Pope John XXIII: Christianity and Social Progress. New York: Paulist Press, 1961.
MLA-referens (8:e uppl.)Catholic Church. Pope (1958-1963 : John XXIII) och William J. Gibbons. Mater Et Magistra: Encyclical Letter of His Holiness Pope John XXIII: Christianity and Social Progress. Paulist Press, 1961.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.