1. (n.d.)Ante-Nicene Fathers, vol. III: The prescription against heretics. Retrieved September 6, 2015, from http://www.tertullian.org/anf/anf03/anf03-24.htm .
2. Benedict XVI (2006). Caritas in veritate. Retrieved from http://w2.vatican.va/content/benedict-xvi/en/encyclicals/documents/hf_ben-xvi_enc_20090629_caritas-in-veritate.html .
3. Brothers, L. (1989). A biological perspective on empathy. The American Journal of Psychiatry, 146, 1.
4. Carey, K. (2015). Gaps in earnings stand out in release of college data. Retrieved September 15, 2015 from http://www.nytimes.com/2015/09/14/upshot/gaps-in-alumni-earnings-stand-out-in-release-of-college-data.html?emc=eta1&_r=0 .
5. Cicero, M., & Grant, M. (1960). Selected works [of] Cicero. Harmondsworth: Penguin.