RT Article T1 Family structure as a predictor of initial substance use and sexual intercourse in early adolescence JF Journal of marriage and family VO 52 IS 1 SP 171 OP 182 A1 Flewelling, Robert L. A2 Bauman, Karl E. LA English YR 1990 UL https://krimdok.uni-tuebingen.de/Record/1637987714 K1 Familienstruktur K1 Drogenkonsum K1 Jugendliche