1. Ainsworth, M. D. (1970). Attachment, exploration, and separation: Illustrated by the behavior of one-year-olds in a strange situation. Child Development, 41(1), 49–67.
2. Ainsworth, M. D. (1972). Individual differences in the development of some attachment behaviors. Merrill Palmer Quarterly, 18(2), 123–143.
3. Ainsworth, M. D. S., Blehar, M. C., Waters, W., & Wall, S. (1978). Patterns of attachment: A psychological study of the strange situation. Hillsdale, NJ: Erlbaum.
4. Bowlby, J. (1940). The influence of early environment in the development of neurosis and neurotic character. International Journal of Psycho-Analysis, 21, 154–178.
5. Bowlby, J. (1944). Forty-four juvenile thieves: Their characters and home-life. International Journal of Psycho-Analysis, 25, 19–53.