RT Article T1 Effectiveness of school-based programs to reduce bullying: a systematic and meta-analytic review JF Journal of experimental criminology VO 7 IS 1 SP 27 OP 56 A1 Ttofi, Maria M. A1 Farrington, David 1944- A2 Farrington, David 1944- LA English YR 2011 UL https://krimdok.uni-tuebingen.de/Record/1912527766 DO 10.1007/s11292-010-9109-1