[On the use of toxic substances. 3rd trial].
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001290:Attitude; D002648:Child; D005191:Family Characteristics; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico; D019966:Substance-Related Disorders / Q000453:epidemiology*
Investigación sobre ul uso de sustancias intoxicantes. Tercera muestra