1. Ainsworth MDS, Blehar Me, Waters E, Wall S (1978) Patterns of attachment: a psychological study of the strange situation. Erlbaum, Hillsdale NJ
2. Andersson BE (1989) Effects of public day-care. A longitudinal study. Child Dev 60:857–866
3. Barglow P, Vaughn BE, Molitor N (1987) Effects of maternal absence due to employment on the quality of infant-mother attachment in a low-risk sample. Child Dev 58:945–954
4. Bell RQ, Chapman M (1986) Child effects in studies using experimental or brief longitudinal approaches to socialization. Dev Psychol 22:595–603
5. Beller KE (1987) Intervention in der frühen Kindheit. In: Oerter R, Montada L (Hrsg) Entwicklungspsychologie. Ein Lehrbuch, 2. Aufl. Psychologie Verlags Union, München, S 789–813