1. Blum R. H. Students and Drugs. Jossey-Bass, San Francisco 1969; 102–109
2. Bogg R. S., Smith R. C., Russell S. D. Drug Dependence in Michigan. Michigan House of Representatives, Special Committee on Narcotics. 1969; 37, 55–56
3. Goode E. The Marijuana Smokers. Basic Books, New York 1970; 201–202
4. Cigarette Smoking and Drug Use on a College Campus