1: De matrimonio christiano : Arcanum divinae Sapientiae 10 febr. 1880, Casti Connubii 31 dec. 1930 - Leo, 13., papa. (OLS)http://ftis/name/72922; Pius, 11., papa. (OLS)http://ftis/name/54439; Hürth, Franz. (OLS)http://ftis/name/66253 (Litterae encyclicae, 1953)