1. Hunt, S.M., McEwen, J. & McKenna, S.P. (1981). Measuring health status. London: Croom Helm.
2. Lewinsohn, P. M., Redner, J. E. & Seeley, J. R. (1991). The relationship between life satisfaction and psychosocial variables: New perspectives. In F. Strack, M. Argyle, & N. Schwarz (Eds.), Subjective well-being: An interdisciplinary perspective (pp. 141–169). Oxford: Pergamon Press.