Wiessing, L., Kraus, L., Hay, G., Rossi, C., Rava, L., Frischer, M., Heatlie, H., Jager, H., Godfrey, C., Carpentier, C., Blum, M., Mickelsson, K. & Hartnoll, R. (2002). European network to develop policy relevant models and socio-economic analyses of drug use, consequences and interventions (EMCDDA Project ERB.4141.PL.980030 Final Report). Lisbon: European Monitoring Centre for Drugs and Drug Addiction.