1. Wong K (2012) http://Blogs.Scientificamerican.Com/Observations/Why-Humans-Give-Birth-To-Helpless-Babies/ . Print
2. Bowlby J (1969/1982) Attachment and loss: vol. 1. Attachment. New York: Basic Books
3. Kopp CB (1989 May) Regulation of distress and negative emotions: a developmental view. Dev Psychol 25(3):343
4. Marvin RS, Britner PA (1999) Normative development: the ontogeny of attachment. In: Cassidy J, Shaver PR (eds) Handbook of attachment theory, research and clinical applications. Guilford Press, New York, pp 44–67
5. Pillai Riddell RR, Chambers CT (2007) Parenting and pain during infancy. In: Anand KJ, Stevens BJ, McGrath BJ (eds) Pain in neonates and infants. Elsevier, Amsterdam, pp 289–298