Source:"The Role of the Media in Promoting and Reducing Tobacco Use. Tobacco Control Monograph No. 19." U.S. Department of Health and Human Services, National Institutes of Health, National Cancer Institute. Bethesda, MD. June 2008.
Source:"Norma R. Broin, et al., Plaintiffs, Vs. Philip Morris Companies, Inc., Defendants. Case No. 91-49738 CA 22. Howard A. Engle, M.D., et al., Plaintiffs, Vs. RJ Reynolds Tobacco Company, Etc., et al., Defendants. Case No. 94-08273 CA 20." Truth Tobacco Industry Documents. 17 Apr. 1997. Deposition.
Source:Federal Trade Commission. Smokeless Tobacco Report for 2017. Retrieved from https://www.ftc.gov/reports/federal-trade-commission-cigarette-report-2017-federal-trade-commission-smokeless-tobacco. Published February, 2019.
Source:Reif, John, Christa Bruns, and Kimberly Lower. “Cancer of the Nasal Cavity and Paranasal Sinuses and Exposure to Environmental Tobacco Smoke in Pet Dogs.” American Journal of Epidemiology. 147(5). 1998. Web.