Catholic Church. Pope (1963-1978 : Paul VI). (1968). Encyclical letter of his Holiness Pope Paul VI: On the regulation of birth : Humanae vitae, issued July 25, 1968. St. Paul Editions.
Chicago Style (17th ed.) CitationCatholic Church. Pope (1963-1978 : Paul VI). Encyclical Letter of His Holiness Pope Paul VI: On the Regulation of Birth : Humanae Vitae, Issued July 25, 1968. Boston, Mass.: St. Paul Editions, 1968.
MLA (8th ed.) CitationCatholic Church. Pope (1963-1978 : Paul VI). Encyclical Letter of His Holiness Pope Paul VI: On the Regulation of Birth : Humanae Vitae, Issued July 25, 1968. St. Paul Editions, 1968.
Warning: These citations may not always be 100% accurate.