Pick, Susan, and Jenna Sirkin. "Behavior as Choice." Breaking the Poverty Cycle: The Human Basis for Sustainable Development. : Oxford University Press, 2010-06-24. Oxford Scholarship Online. 2010-09-01. Date Accessed 19 Jun. 2013 <http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195383164.001.0001/acprof-9780195383164-chapter-007>.
Pick, S., & Sirkin, J.(2010-06-24). Behavior as Choice. In Breaking the Poverty Cycle: The Human Basis for Sustainable Development. : Oxford University Press. Retrieved 19 Jun. 2013, from http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195383164.001.0001/acprof-9780195383164-chapter-007.
Pick, Susan, and Jenna Sirkin. "Behavior as Choice." In Breaking the Poverty Cycle: The Human Basis for Sustainable Development. : Oxford University Press, 2010-06-24. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195383164.001.0001/acprof-9780195383164-chapter-007.
Pick S, Sirkin J. Behavior as Choice. In: Pick S, Sirkin J. Breaking the Poverty Cycle: The Human Basis for Sustainable Development. Oxford University Press; 2010. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195383164.001.0001/acprof-9780195383164-chapter-007. Accessed June 19, 2013.