To cite a web site, follow this basic format:
Author AA [if there is one; otherwise, use the name of the
agency or group responsible for the web site]. Title
of page. Available at: URL. Accessed [date you
accessed it].
Centers For Disease Control and Prevention. Health effects
of cigarette smoking. Available at:
http://www.cdc.gov/tobacco/data_statistics/
fact_sheets/health_effects/
effects_cig_smoking/. Accessed June 27, 2013.