U.S. Department of Health, Education, and Welfare. Proceedings, 3rd World Conference Smoking & Health: Modifying the risk for the smoker. U.S. Department of Health, Education, and Welfare, Public Health Service, National Institutes of Health, National Cancer Institute. Washington, DC: U.S. Department of Health, 2018.

U.S. Department of Health, Education, and Welfare. Proceedings, 3rd World Conference Smoking & Health: Modifying the risk for the smoker. U.S. Department of Health, Education, and Welfare, Public Health Service, National Institutes of Health, National Cancer Institute. Washington, DC: U.S. Department of Health, 2018.