“The Health Consequences of Smoking—50 Years of Progress: A Report of the Surgeon General, 2014,” http://www.surgeongeneral.gov/library/reports/50-years-of-progress/#fullreport, accessed September 1, 2016.

Max, W., H.Y. Sung, S. Yanling, B. Start, “The Cost of Smoking in California, 2009” Institute for Health & Aging, School of Nursing University of California, San Francisco.