1. Statistics and Information Department, Minister’s Secretariat, Ministry of Health and Welfare ed: Vital Statistics, 1947–1997, Kosei-tokei-kyokai, Tokyo, 1949–1999 (in Japanese).
2. Health Service Bureau of the Ministry of Health and Welfare ed: Cancer ’90 in Figures; A Report of the Fifth National Survey on Malignant Neoplasms, Sogoigakusha, Tokyo, 1990 (in Japanese).
3. Health and Welfare Bureau for the Elderly of the Ministry of Health and Welfare ed: Handbook of Health Services for the Elderly, 1993, Daiichi-hoki-shuppan, Tokyo, 1993 (in Japanese).
4. Statistics and Information Department, Minister’s Secretariat, Ministry of Health and Welfare ed: Report of the Health Services for the Elderly, 1996, Kosei-tokei-kyokai, Tokyo, 1998 (in Japanese).
5. Statistics and Information Department, Minister’s Secretariat, Ministry of Health and Welfare ed: Fundamental tables edited from magnetic tape copies with the official permission of the Management and Coordination Agency on “Report of the Health Services for the Elderly, 1983-1995”.