APA

[John Paul II], . (1987). Sollicitudo rei socialis : encyclical letter 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: United States Cathgolic Conference.

Chicago

[John Paul II], . 1987. Sollicitudo rei socialis : encyclical letter 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: United States Cathgolic Conference.

Harvard

[John Paul II], . (1987). Sollicitudo rei socialis : encyclical letter 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: United States Cathgolic Conference.

MLA

[John Paul II], . Sollicitudo rei socialis : encyclical letter 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: United States Cathgolic Conference. 1987.