1. 1. Ericksoa E: Childhood and Society ed 2. New York W.W. Norton. 1963.
2. 2. Schuster C Ashburn S: The Process of Human Development: A Holistic Approach. Boston Little Brown & Co 1980.
3. 3. Birren J Renner J: Research on the psychology of aging: Principles and experimentations in Birren J Schaie K (eds): Handbook of the Psychology of Aging. New York Van Mostrane! Reinhold Co 1977.
4. 4. Jourard S: The Transparent Self: Self Disclosure and Well-Being. New York Van Nostrand Reinhold Co 1964.
5. 5. teck R: Physiological developments in the second half of life in Sze W (ed): Human Life Cycle. New York Jason Aronson Inc. 1975.