Reichskonkordat

http://en.wikipedia.org/wiki/Reichskonkordat

http://en.wikipedia.org/wiki/Mit_brennender_Sorge

http://en.wikipedia.org/wiki/Catholic_sex_abuse_cases

http://en.wikipedia.org/wiki/Humani_generis_unitas

http://www.vatican.va/holy_father/pius_xi/encyclicals/documents/hf_p-xi_enc_19031937_divini-redemptoris_en.html