1. http://oxforddictionaries.com/view/entry/m_en_gb0259160#m_en_gb0259160[accessed 29.04.11].
2. http://oxforddictionaries.com/view/entry/m_en_gb0013180#m_en_gb0013180[accessed 29.04.11].
3. http://www.who.int/healthinfo/survey/ageingdefnolder/en/index.html [accessed 29.04.11].
4. An international comparison of trends in disability-free life expectancy;Cambois;Developments in Health Economics and Public Policy,1996
5. Ageing populations: the challenges ahead;Christensen;Lancet,2009