1. World Health Organisation: Definition of an older or elderly person. In.; 2002.
2. Department of Economic and Social Affairs: Population ageing and development: Ten years after Madrid. In: Population Facts. Population Division, United Nations 2012.
3. Department of Economic and Social Affairs Population Division. Population ageing and development: ten years after Madrid. In: Population Facts. United Nations; 2012.
4. Gray AM, Clarke PM, Wolstenholme JL, Wordsworth S. Applied methods of cost-effectiveness analysis in health care. United States: Oxford University Press; 2011.
5. Drummond M, Sculpher MJ, Torrance GW, O’Brien BJ, Stoddart GL. Methods for the economic evaluation of health care programmes. 3rd ed. New York: Oxford University Press; 2005.