Engel, G.L. (1975). The death of a twin: Mourning and anniversary reactions. Fragments of 10 years of self-analysis. International Journal of Psycho-Analysis, 56: 23-40.
Hayton, A. (2009). Attachment issues associated with the loss of a co-twin before birth. Attachment: New Directions in Psychotherapy and Relational Psychoanalysis, 3: 144-156.
Additional References/Resources (partial list)
Ainslie, R. (1997). The psychology of twinship. Northvale: Jason Aronson.Burlingham, D. T. (1949). The relationship of twins to each other. Psychoanalytic Study of the Child, 3: 57-72.
Burlingham, D. T. (1963). A study of identical twins—their analytic material compared with existing observation data of their early childhood. Psychoanalytic Study of the Child, 18: 367-423.
Friedman, J. A. (2008). Emotionally healthy twins. Philadelphia: Perseus Books.
Friedman, J. A. (2014). The same but different. Los Angeles: Rocky Pines.
Friedman, J. A. (2018). Twins in session: Case histories in treating twinship issues. Los Angeles: Rocky Pines.
Piontelli, A., Piontelli, A., Bocconi, L., Kusterman, A., Butt, K., Osborne, J., & O'Brien, G. (1997). Patterns of evoked behaviour in twin pregnancies during the first 22 weeks of gestation. Early Human Development, 50: 39-45.
Segal, N. L. (2000). Entwined lives: Twins and what they tell us about human behavior. New York: Plume.
Segal, N, L. & Ream, S. L. (1998). Decrease in grief intensity for deceased twin and non-twin relatives: An evolutionary perspective. Personality and Individual Differences, 25: 317-325.
Woodward, J. (1998, 2nd edition in 2010). Lone twin: Understanding twin bereavement and loss. London: Free Association.
Lone Twin (D: Anna van der Wee, 2011). Brussels, Belgium: Wild Heart Productions.