Widiger, Thomas A., and Jennifer Ruth Presnall. "Pathological Altruism and Personality Disorder." Pathological Altruism. : Oxford University Press, 2011-12-09. Oxford Scholarship Online. 2012-01-19. Date Accessed 24 May. 2013 <http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780199738571.001.0001/acprof-9780199738571-chapter-006>.
Widiger, T., & Presnall, J.(2011-12-09). Pathological Altruism and Personality Disorder. In Pathological Altruism. : Oxford University Press. Retrieved 24 May. 2013, from http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780199738571.001.0001/acprof-9780199738571-chapter-006.
Widiger, Thomas A., and Jennifer Ruth Presnall. "Pathological Altruism and Personality Disorder." In Pathological Altruism. : Oxford University Press, 2011-12-09. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780199738571.001.0001/acprof-9780199738571-chapter-006.
Widiger TA, Presnall JR. Pathological Altruism and Personality Disorder. In: Oakley B, Knafo A, Madhavan G, Wilson DS. Pathological Altruism. Oxford University Press; 2011. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780199738571.001.0001/acprof-9780199738571-chapter-006. Accessed May 24, 2013.