APA-viite (7. p.)

Paul VI, P. (1968). On the regulation of birth = Humanae vitae: Encyclical letter. Washington, D.C..

Chicago-viite (17. p.)

Paul VI, Pope. On the Regulation of Birth = Humanae Vitae: Encyclical Letter. Washington, D.C., 1968.

MLA-viite (8. p.)

Paul VI, Pope. On the Regulation of Birth = Humanae Vitae: Encyclical Letter. Washington, D.C., 1968.