Sandwijk, J. P., Cohen, P., & Musterd, S. (1991). Licit and illicit drug use in Amsterdam: Report of a household survey in 1990 on the prevalence of drug use among the population of 12 years and over. Onderzoekprogramma Drugbeleid gemeente Amsterdam.
Cita Chicago Style (17a ed.)Sandwijk, J. P., Peter Cohen, y Sako Musterd. "Licit and Illicit Drug Use in Amsterdam: Report of a Household Survey in 1990 on the Prevalence of Drug Use Among the Population of 12 Years and over." Onderzoekprogramma Drugbeleid Gemeente Amsterdam 1991.
Cita MLA (9a ed.)Sandwijk, J. P., et al. "Licit and Illicit Drug Use in Amsterdam: Report of a Household Survey in 1990 on the Prevalence of Drug Use Among the Population of 12 Years and over." Onderzoekprogramma Drugbeleid Gemeente Amsterdam, 1991.