Chapter, §

 1   1, 4(1)  |                    See Pius IX, encyc.letter Oui pluribus: Pii
 2   1, 4(1)  |         1, pp. 9-10; St. Pius X encyc.letter Singulari quadam:
 3   1, 4(1)  |         4 (1912), 658; Pius XI, encyc.letter Casti connubii: AAS
 4   1, 4(1)  |     1954), 671-672; John XXIII, encyc.letter Mater et Magistra:
 5   1, 4(4)  |       Part II, ch. 8; Leo XIII, encyc.letter Arcanum: Acta Leonis
 6   1, 4(4)  |          1880), 26-29; Pius XI, encyc.letter Divini illius Magistri:
 7   1, 4(4)  | Magistri: AAS 22 (1930), 58-61; encyc.letter Casti connubii: AAS
 8   1, 4(4)  |       VI, 394-395]; John XXIII, encyc.letter Mater et Magistra:
 9   2, 11(12)|                    See Pius XI. encyc. letter Casti connubi: AAS
10   2, 13(13)|                             See encyc.letter Mater et Magistra:
11   2, 14(14)|        Part II, ch. 8; Pius XI, encyc.letter Casti connubii: AAS
12   2, 14(14)|     1951), 857-859; John XXIII, encyc.letter Pacem in terris:
13   2, 14(15)|                    See Pius XI, encyc.letter Casti connubii: AAS
14   2, 14(16)|        Part II, ch. 8; Pius XI, encyc.letter Casti connubii: AAS
15   2, 14(16)|       VI, 394-395]; John XXIII, encyc.letter Mater et Magistra:
16   2, 18(23)|                    See Paul Vl, encyc.letter Populorum progressio:
17   3, 23(26)|                                 Encyc.letter Mater et Magistra:
18   3, 23(27)|                             See encyc.letter Populorum progressio,