Gaya APA

XI, P. (-1954). Quadragesimo anno, encyclical letter on the social order and perfecting it conformably to the precepts of the gospel, in commemoration of the fortieth anniversary of the encyclical letter 'Rerum Novarum' . London dsl: Catholic Truth Society dsl.

Gaya MLA

XI, Pius. "Quadragesimo anno, encyclical letter on the social order and perfecting it conformably to the precepts of the gospel, in commemoration of the fortieth anniversary of the encyclical letter 'Rerum Novarum' ". London dsl: Catholic Truth Society dsl, -1954. Buku.