Core data for epidemiological studies of nonmedical drug use. 

 - 100 p. 
 - WHO offset publications ; no. 56 .
<br/><br/><label>ISBN: </label>9241700564 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Substance abuse--Epidemiology<br/>Substance-related disorders--Epidemiology<br/>Data collection--Methods