論文（英文）
The effect of aging on functional decline among older Japanese living in a community: a 5-year longitudinal data analysis.
Ishizaki T, Kai I, Kobayashi Y, Matsuyama Y, and Imanaka Y. The effect of aging on functional decline among older Japanese living in a community: a 5-year longitudinal data analysis. Aging Clinical and Experimental Research 2004; 16: 233-239.