MacKesyamiti, M; Fendrich, M; Goldstein, PJ (1997). "Sequence of drug use among serious drug users: typical vs atypical progression". Drug and Alcohol Dependence 45 (3): 185–96. DOI:10.1016/S0376-8716(97)00032-X. PMID 9179520.
Reinarman, C. ; Cohen, P. D. A. ; Kaal, H. L. (2004). "The Limited Relevance of Drug Policy: Cannabis in Amsterdam and in San Francisco". American Journal of Public Health 94 (5): 836–42. DOI:10.2105/AJPH.94.5.836. PMC 1448346. PMID 15117709.
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The "Gateway" theory: Does cannabis use lead to hard drugs? Drug use progression and the gateway effect [۱]بایگانیشده در ۲۲ ژوئن ۲۰۱۲ توسط Wayback Machine
The "Gateway" theory: Does cannabis use lead to hard drugs? Drug use progression and the gateway effect [۱]بایگانیشده در ۲۲ ژوئن ۲۰۱۲ توسط Wayback Machine