1. Crumpacker, D. W. A twin methodology for the study of genetic and environmental control variation in human smoking behavior. Acta Genetica Medico. Gemellol 28: 173–195, 1979.
2. Shields, J. Heredity and Environment. In H. J. Eysenck & G. D. Wilson (Eds.), A Textbook of Human Psychology. Lancaster, England: MTP Press, 1976.
3. Smart, R. G., Mora, M. E., Terroba, G., & Varma, V. K. Drug use among non-students in three countries. Drug and Alcohol Dependence 7: 125–132, 1981.
4. Johnston, L. P., Bachman, J. G., & CMalley, P. M. Drugs and the nation’s high school students. In G. G. Nahas & H. C. Frick (Eds.), Drug Abuse in the Modern World. New York: Pergamon Press, 1981.
5. Siegel, R. K. Street drugs 1977: Changing patterns of recreational use. In S. Cohen (Ed.), Drug Abuse and Alcoholism: Current Critical Issues. New York: Haworth Press, 1981.