Perceived availability and the use of drugs.
D000293:Adolescent; D005260:Female; D006801:Humans; D013287:Illicit Drugs / Q000600:supply & distribution*; D008297:Male; D009864:Ontario; D004364:Pharmaceutical Preparations / Q000600:supply & distribution*; D019966:Substance-Related Disorders / Q000453:epidemiology*; D011795:Surveys and Questionnaires
D013287:Illicit Drugs; D004364:Pharmaceutical Preparations