1. Class Struggle and the Magisterium: A New Note;Baum;Theological Studies,1984
2. Benedict XVI , Pope 2009 Caritas in veritate http://w2.vatican.va/content/benedict-xvi/en/encyclicals/documents/hf_ben-xvi_enc_20090629_caritas-in-veritate.html
3. Benedict XVI , Pope 2011 Message of His Holiness Benedict XVI for the World Mission Sunday 2011 http://www.vatican.va/holy_father/benedict_xvi/messages/missions/documents/hf_ben-xvi_mes_20110106_world-mission-day-2011_en.html
4. Karl Rahner on the Radical Unity of the Love of God and Neighbor;Beyer;Irish Theological Quarterly,2003