Many of these church documents are concerned primarily with marriage, whilst others address it indirectly. 

1. Casti Connubii (Pope Pius XI, 31 Dec 1930):
Castī Connūbiī (Latin: "of chaste wedlock") was a papal encyclical promulgated by Pope Pius XI on December 31, 1930 in response to the Lambeth Conference of the Anglican church. It stressed the sanctity of marriage, prohibited Catholics from using any form of artificial birth control, and reaffirmed the prohibition on abortion. It also explained the authority of Church doctrine on moral matters, and advocated that civil governments follow the lead of the Church in this area.

2. Humanae Vitae (Pope Paul VI, 25 July 1978):
Humanae Vitae is an encyclical written by Pope Paul VI and issued on 25 July 1968. This encyclical re-affirms the traditional teaching of the Catholic Church regarding married love, responsible parenthood, and the continued rejection of all forms of contraception. Mainly because of its prohibition of all forms of artificial contraception, the encyclical was extremely controversial. In it, Pope Paul VI maintained the Church's long-standing teaching, rejecting the opinion offered by the majority of the commission he had charged with studying the subject. In 2008, Pope Benedict XVI called this topic "so controversial, yet so crucial for humanity's future". Humanae Vitae became "a sign of contradiction but also of continuity of the Church's doctrine and tradition... What was true yesterday is true also today."

3. Gaudium et Spes (Pope Paul VI, 7 Dec 1965):
Gaudium et Spes (Latin: Joy and Hope), the Pastoral Constitution on the Church in the Modern World, was one of the four Apostolic Constitutions resulting from the Second Vatican Council. The document is an overview of the Catholic Church's teachings about humanity's relationship to society, especially in reference to economics, poverty, social justice, culture, science, technology and ecumenism.

4. Familiaris Consortio (Pope John Paul II, 22 Nov 1981):
Familiaris Consortio (On the role of the Christian Family in the Modern World) is a postsynodal Apostolic Exhortation written by Pope John Paul II and promulgated on November 22, 1981. It describes the official position of the Roman Catholic Church concerning the meaning and role of marriage and the family, and outlines challenges towards realizing that ideal. It defines marriage "as a personal union in which the spouses reciprocally give and receive."