1. Patterns of attachment;Ainsworth,1978
2. Toward a substantive theory of mother-twin attachment;Anderson;MCN: The American Journal of Maternal-Child Nursing,1990
3. Psycho-social development during infancy;Ashburn,1980
4. The multiple birth explosion: Implications for nursing practice;Journal of Obstetric, Gynecologic, and Neonatal Nursing,1998
5. The nature of the child’s tie to his mother;Bowlby;International Journal of Psychoanalysis,1958