1. Ainsworth, M. D., Blehar, M. C., Waters, E. & Wall, S. (1978). Patterns of attachment: A psychological study of the strange situation. Hillsdale, NJ: Erlbaum.
2. Azuma, H. (1999). The discipline and teaching of children by Japanese mothers (4th ed.). Tokyo: Tokyo University Press.
3. Azuma, H., Kashiwagi, K. & Hess, R. D. (1999). The relationship between attitude and behavior in the mother and a child's intelligence (9th ed.). Tokyo: Tokyo University Press.
4. Developmental changes in maternal interactions with term and preterm infants