00000nam a2200000 a 4500 Bless, Ruud aut Verfasser/-in Korf, Dirk aut Verfasser/-in Freeman, M. aut Verfasser/-in Open Drug Scenes A Cross-National Comparison of Concepts and Urban Strategies R. Bless ; Dirk J. Korf ; M. Freeman Basel [u.a.] Karger 1995 eng European Addiction Research