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2. European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) Annual Report: The State of the Drugs Problem in Europe 2011
3. Dipartimento Politiche Antidroga (DPA) Relazione annuale al parlamento sull'uso delle sostanze stupefacenti e sulle tossicodipendenze in Italia 2012
4. International Narcotics Control Board (INCB) Report of the International Narcotics Control Board for 2011 2011
5. High potency cannabis: the forgotten variable;Smith;Addiction,2005