1. Aiken, L. R. (2001).Aging and later life. Illinois; Charles C. Thomas Publisher
2. Antonucci, T. C. (1990). Social support and social relationships. In R. H. Binstock & L. K. George (Eds.),Handbook of aging and the social sciences(3rd ed., pp. 205–226). New York: Academic.
3. Arbuckle, J. & Wothke, W. (1999).Amos 4.0 use’s guide. Chicago, IL: Small Waters Corporation.
4. Cutler, S. J. & Handricks, J. (1990) Leisure and time use across the life course. In R. H. Binstock & L. K. George (Eds.),Handbook of aging and the social sciences(3rd. ed. pp. 158–169). New York: Academic Press.
5. Czaja, S. J. (1997). Computer technology and the older adult. In M. G. Helander, T. K. Landauer, & P. V. Prabue (Eds.),Handbook of human computer interaction(2nd ed. pp. 797–812). New York: Elsevier Science.