1. WHO, Tobacco fact sheet 339. Available at .
2. WHO, Cancer fact sheet 339. Available at .
3. U.S. Department of Health and Human Services, Changing adolescent smoking prevalence, Smoking and Tobacco Control Monograph 14, 2001, 85–89.
4. Peer pressure to smoke: the meaning depends on the method;Michell;Health Educ. Res.,1996
5. Tobacco use, Targeting the Nations leading killer. Available at .