RT Article T1 Ambivalence toward methadone treatment among intravenous drug users JF Journal of psychoactive drugs VO 23 IS 1 SP 21 OP 28 A1 Rosenblum, A. A2 Magura, S. A2 Joseph, H. LA English YR 1991 UL https://krimdok.uni-tuebingen.de/Record/1640047395 K1 Methadon