RT Article T1 Adolescent sexual activity and pregnancy: socioenvironmental problems, physical health, and mental health JF Journal of youth and adolescence VO 16 IS 5 A2 Stiffman, Arlene R. LA English YR 1987 UL https://krimdok.uni-tuebingen.de/Record/1642548898 K1 Schwangerschaft K1 Jugendliche