"The Vindication of Humanae Vitae" at First Things. Social science has vindicated Humanae Vitae's predictions. No one wants to hear that, however.
Bishop Baker of Birmingham has issued a letter on the 40th anniversary of Paul VI's prophetic encyclica. [H/t. Annunciations] in which he recommends: A Study Guide to Humane Vitae, Of Human Life. and this pamphlet by Janet Smith" Sex and Contraception.
Dr. Smith's classic is "Contraception: Why Not"
And sure, go back and read the encyclical that received "the execration of the world."