1. Adrian, M.J. (1981). Flexibility in the aging adult. In E.L. Smith and R.C. Serfass (Eds.), Exercise and aging: The scientific basis. Hillside, NJ: Enslow.
2. Andersen, K.L., Masironi, R., Rutenfranz, J., & Seliger, V. (1978). Habitual physical activity and health. Copenhagen: World Health Association.
3. Andersen, K.L., Shephard, R.J., Denolin, H., Varnauskas, E., & Masironi, R. (1971). Fundamentals of exercise testing. Geneva: World Health Organization.
4. Astrand, P.O. & Rodahl, K. (1977). Textbook of work physiology. New York: McGraw-Hill.
5. Barry, A.J., Steinmetz, J.R., Page, H.F., & Rodahal, K. (1966). The effects of physical conditioning on older individuals. II. Motor performance and cognitive function. Journal of Gerontology, 21, 192–199.