1. Service Needs of the Elderly in the 21st Century: Factors Driving Demand;The Urban Institute.;Policy and Research Report,1989
2. Health service needs of the oldest old;Soldo;Milbank Mem Fund Q,1985
3. Bureau of the Census. Estimates of the Population of the United States, by Single Years of Age, Color and Sex U.S. Department of Commerce
4. Bureau of the Census. Projections of the Population of the United States, by Age, Sex, and Race: 1983 to 2080 U.S. Department of Commerce