Prorok, J. C.; Iserman, E. C.; Wilczynski, N. L.; Haynes, R. B. (September 10, 2012). "The quality, breadth, and timeliness of content updating vary substantially for 10 online medical texts: an analytic survey". Journal of Clinical Epidemiology. 65 (12): 1289–95. doi:10.1016/j.jclinepi.2012.05.003. PMID22974495.
Prorok, J. C.; Iserman, E. C.; Wilczynski, N. L.; Haynes, R. B. (September 10, 2012). "The quality, breadth, and timeliness of content updating vary substantially for 10 online medical texts: an analytic survey". Journal of Clinical Epidemiology. 65 (12): 1289–95. doi:10.1016/j.jclinepi.2012.05.003. PMID22974495.