References
- Biernacki P., Waldorf D. Snowball sampling-problems and techniques of chain referral sampling. Sociological Methods and Research 1981; 10: 141–163
- Bryman A., Burgess R. G. Analyzing qualitative data. Routledge, London 1999
- Creswell J. W. Qualitative inquiry and research design—Choosing among five traditions. Sage, USA 1998
- Diaz A., Barruti M., Doncel C. The lines of success? A study on the nature and extent of cocaine use in Barcelona. Laboratori de Sociologia/ICESB, Barcelona 1992
- Kandel D. B., Yamaguchi K. From beer to crack: Developmental patterns of drug involvement. American Journal of Public Health 1993; 83(6)851–855
- Mackesy-Amiti M. E., Fendrich M., Goldstein P. J. Sequence of drug use among serious drug users: Typical vs. atypical progression. Drug and Alcohol Dependence 1997; 45: 185–196
- McCance E. F., Price L. H., Kosten T. R., Jatlow P. I. Cocaethylene: Pharmacology, physiology and behavioral effects in humans. Journal of Pharmacology and Experimental Therapeutics 1995; 274(1)215–223
- Nappo S. A., Galduróz J. C. F., Noto A. R. Crack use in São Paulo. Substance Use & Misuse 1996; 31(5)565–579
- Patton M. Q. Qualitative evaluation and research methods. Sage, London 1990
- Scivoletto S., Henriques S. G., Jr., Andrade A. G. A progressão do consumo de drogas entre adolescentes que procuram tratamento. Jornal Brasileiro de Psiquiatria 1996; 45(4)201–207
- Siegel R. K. New patterns of cocaine use: changing doses and routes. Cocaine use in America: Epidemiologic and clinical perspective, N. Kozel, E. H. Adams. NIDA, Rockville, MD 1985
- Stebancka M., Allebeck P., Romelsjo A. Initiation into drug abuse: The pathway from being offered drugs to trying cannabis and progression to intravenous drug abuse. Scandinavian Journal of Social Medicine 1993; 21(1)31–39
- World Health Organization. Qualitative research for health programmes. Division of Mental Health, Geneva 1994; 1–102
- Yamaguchi K., Kandel D. B. Patterns of drug use from adolescence to young adulthood: II—Sequences of Progression. American Journal of Public Health 1984; 74(7)668–672