HSING, ANN W., ASIF RASHID, SUSAN S. DEVESA, and JOSEPH F. FRAUMENI. "Biliary Tract Cancer." Cancer Epidemiology and Prevention. : Oxford University Press, 2006-10-12. Oxford Scholarship Online. 2009-09-01. Date Accessed 21 May. 2013 <http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195149616.001.0001/acprof-9780195149616-chapter-40>.
HSING, A., RASHID, A., DEVESA, S., & FRAUMENI, J.(2006-10-12). Biliary Tract Cancer. In Cancer Epidemiology and Prevention. : Oxford University Press. Retrieved 21 May. 2013, from http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195149616.001.0001/acprof-9780195149616-chapter-40.
HSING, ANN W., ASIF RASHID, SUSAN S. DEVESA, and JOSEPH F. FRAUMENI. "Biliary Tract Cancer." In Cancer Epidemiology and Prevention. : Oxford University Press, 2006-10-12. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195149616.001.0001/acprof-9780195149616-chapter-40.
HSING AW, RASHID A, DEVESA SS, FRAUMENI JF. Biliary Tract Cancer. In: Schottenfeld D, Fraumeni JF. Cancer Epidemiology and Prevention. Oxford University Press; 2006. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195149616.001.0001/acprof-9780195149616-chapter-40. Accessed May 21, 2013.