Winker, Margaret A., and Stephen J. Lurie. "Case-Control Studies." AMA Manual of Style. 20090401. Oxford University Press. Date of access 24 May. 2013, <http://www.amamanualofstyle.com/view/10.1093/jama/9780195176339.001.0001/med-9780195176339-div2-526>.
Winker, M., & Lurie, S. (20090401). Case-Control Studies. AMA Manual of Style. Retrieved 24 May. 2013, from http://www.amamanualofstyle.com/view/10.1093/jama/9780195176339.001.0001/med-9780195176339-div2-526.
Winker, Margaret A., and Stephen J. Lurie. "Case-Control Studies." AMA Manual of Style. 24 May. 2013. http://www.amamanualofstyle.com/view/10.1093/jama/9780195176339.001.0001/med-9780195176339-div2-526.
Winker MA, Lurie SJ. Case-control studies. In: AMA Manual of Style Committee. AMA Manual of Style: A Guide for Authors and Editors. 10th ed. New York, NY: Oxford University Press; 2007. http://www.amamanualofstyle.com/view/10.1093/jama/9780195176339.001.0001/med-9780195176339-div2-526. Accessed May 24, 2013.