1. Centro di Medicina Preventiva, Verona, Italy.
2. Dipartimento delle Dipendenze, Verona, Italy.
3. Osservatorio Regionale Dipendenza, Regione Veneto, Italy.
4. Department of Psychology, Iowa State University, Ames, Iowa.
5. Institute of Science and Society, Iowa State University, Ames, Iowa.
6. National Institute on Media and the Family, Minneapolis, Minnesota.