John Paul II, P. (1987). On the twelfth centenary of the second council of Nicaea: Duodecimum saeculum : apostolic letter, December 4, 1987. Washington, D.C..
Chicago-referens (17:e uppl.)John Paul II, Pope. On the Twelfth Centenary of the Second Council of Nicaea: Duodecimum Saeculum : Apostolic Letter, December 4, 1987. Washington, D.C., 1987.
MLA-referens (8:e uppl.)John Paul II, Pope. On the Twelfth Centenary of the Second Council of Nicaea: Duodecimum Saeculum : Apostolic Letter, December 4, 1987. Washington, D.C., 1987.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.