Lurie, Stephen J., and Margaret A. Winker. "Ordinals." AMA Manual of Style. 20090401. Oxford University Press. Date of access 18 May. 2013, <http://www.amamanualofstyle.com/view/10.1093/jama/9780195176339.001.0001/med-9780195176339-div2-510>.
Lurie, S., & Winker, M. (20090401). Ordinals. AMA Manual of Style. Retrieved 18 May. 2013, from http://www.amamanualofstyle.com/view/10.1093/jama/9780195176339.001.0001/med-9780195176339-div2-510.
Lurie, Stephen J., and Margaret A. Winker. "Ordinals." AMA Manual of Style. 18 May. 2013. http://www.amamanualofstyle.com/view/10.1093/jama/9780195176339.001.0001/med-9780195176339-div2-510.
Lurie SJ, Winker MA. Ordinals. In: AMA Manual of Style Committee. AMA Manual of Style: A Guide for Authors and Editors. 10th edition ed. New York, NY: Oxford University Press; 2007:825-826. http://www.amamanualofstyle.com/view/10.1093/jama/9780195176339.001.0001/med-9780195176339-div2-510. Accessed May 18, 2013.