RT Article T1 Cleaning up drug hot spots in Oakland, California: the displacement and diffusion effects JF Justice quarterly VO 12 IS 4 SP 737 OP 754 A1 Green, Lorraine LA English YR 1995 UL https://krimdok.uni-tuebingen.de/Record/163963245X K1 Drogenhandel K1 Verdrängungseffekte K1 Polizeikontrolle K1 USA