1. WHO Methods for Life Expectancy and Healthy Life Expectancy,2014
2. WHO World Health Report 2008: Primary Health Care Now More Than Ever,2008
3. World Population Aging 2009;Department of Economic and Social Affairs (DESA),2009
4. The oldest old;Campion;N Engl J Med,1994
5. Restricted activity days among older adults;Kosorok;Am J Public Health,1992