RT Article T1 Disruptiveness, friends' characteristics, and delinquency in early adolescence: a test of two competing models of development JF Child development VO 68 IS 4 SP 676 OP 689 A1 Vitaro, Frank LA English YR 1997 UL https://krimdok.uni-tuebingen.de/Record/1639819185 K1 Jugendliche K1 Jugenddelinquenz K1 Peereinfluss K1 Aggressivität