Encyclical letter. Mater et Magistra of His Holiness John XXIII by Divine Providence Pope. To His Venerable Brethern the patriarchs, primates, archbishops, bishops, and all other local ordinaries that are at peace and in communion with the Apostolic See, and to the clergy and faithful of the entire Catholic world concerning a re-valuation of the social question in the light of Christian teaching /
Catholic Church. [Popes. - John XXIII. 1958-63.]
London, 
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