1. United Nations. Department of Economic Social Affairs: World population ageing 2009. 2009, New York
2. World urbanization prospects: the 2005 revision. http://www.un.org/esa/population/publications/WUP2005/2005wup.htm ,
3. World Health Organization: Global age-friendly cities: a guide. 2007, Geneva
4. Chodzko-Zajko WJ, Proctor DN, Fiatarone Singh MA, Minson CT, Nigg CR, Salem GJ, Skinner JS: Exercise and physical activity for older adults. Med Sci Sports Exerc. 2009, 41 (7): 1510-1530. 10.1249/MSS.0b013e3181a0c95c. 1510.1249/MSS.1510b1013e3181a1510c1595c
5. World Health Organization: Active ageing: a policy framework. 2002, Geneva