1. IARC (2007) Smokeless tobacco and some tobacco-specific N-nitrosamines. IARC monographs on the evaluation of carcinogenic risks to humans, vol 89. IARC Press, Lyon, p 370
2. IARC (2012) IARC Summary of Classifications, vol 1–106. IARC Press, Lyon, p 31
3. Rodu B, Jansson C (2004) Smokeless tobacco and oral cancer: a review of the risks and determinants. Crit Rev Oral Biol Med 15:252–263
4. Royal College of Physicians (2007) Harm reduction in nicotine addiction: helping people who can’t quit. A report by the Tobacco Advisory Group of the Royal College of Physicians, London
5. FDA (2012) Harmful and Potentially Harmful Constituents in Tobacco Products and Tobacco Smoke: Established List. ( http://www.fda.gov/TobaccoProducts/GuidanceComplianceRegulatoryInformation/ucm297786.htm )