1. Berg, S., Mellstrom, D., Persson, G., & Svanborg, A. (1981). Loneliness in the Swedish aged. Journal of Gerontology. 36. 342–349.
2. Blau, Z. (1961). Structural constraints of friendship in old age. American Sociological Review
26. 429–439.
3. Bradburn, N. (1969). The structure of psychological well-being. Chicago: Aldine.
4. Bragg, M. E. (1979). A comparative study of loneliness and depression (Doctoral dissertation, University of California, Los Angeles). Dissertation Abstracts International. 39, 79–13710.
5. Brennan, T., & Auslander, N. (1979). Adolescent loneliness: An exploratory study of social and psychological predisposition and theory. (National Institute of Mental Health, Juvenile Problems Division, Grant No. ROI-MH 289 12–01 ). Boulder, CO.: Behavioral Research Institute.