[Pius XI, Pope]..
Encyclical letter of His Holiness Pius XI by divine providence Pope to the patriarchs, primates, archbishops, bishops and other ordinaries in peace and communion with the apostolic see and to all the faithful of the Catholic world on Christian education o /

. - Vatican  : Vatican Polyglot Press,  1929 
. - 35 p.  27 cm. 
<br/>К.: Бібліогр. в підрядк. прим.