Catholic Church. Pope (1978-2005 : John Paul II) & John Paul II, P. (1988). Encyclical letter Sollicitudo rei socialis of the supreme pontiff, John Paul II, to the bishops, priests, religious families, sons and daughters of the church and all people of good will for the twentieth anniversary of Populorum progressio. Office of Publishing and Promotion Services, United States Catholic Conference.
Παραπομπή σε μορφή Chicago (17η εκδ.)Catholic Church. Pope (1978-2005 : John Paul II) και Pope John Paul II. Encyclical Letter Sollicitudo Rei Socialis of the Supreme Pontiff, John Paul II, to the Bishops, Priests, Religious Families, Sons and Daughters of the Church and All People of Good Will for the Twentieth Anniversary of Populorum Progressio. Washington, D.C.: Office of Publishing and Promotion Services, United States Catholic Conference, 1988.
Παραπομπή σε μορφή MLA (8th εκδ.)Catholic Church. Pope (1978-2005 : John Paul II) και Pope John Paul II. Encyclical Letter Sollicitudo Rei Socialis of the Supreme Pontiff, John Paul II, to the Bishops, Priests, Religious Families, Sons and Daughters of the Church and All People of Good Will for the Twentieth Anniversary of Populorum Progressio. Office of Publishing and Promotion Services, United States Catholic Conference, 1988.