Applied Epidemiology: Theory to practice. : Oxford University Press, 2006-08-17. Oxford Scholarship Online. 2009-09-01. Date Accessed 26 May. 2013 <http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195187410.001.0001/acprof-9780195187410>.
(2006-08-17). Applied Epidemiology: Theory to practice. : Oxford University Press. Retrieved 26 May. 2013, from http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195187410.001.0001/acprof-9780195187410.
Applied Epidemiology: Theory to practice. : Oxford University Press, 2006-08-17. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195187410.001.0001/acprof-9780195187410.
Brownson RC, Petitti DB. Applied Epidemiology: Theory to practice. Oxford University Press; 2006. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195187410.001.0001/acprof-9780195187410. Accessed May 26, 2013.