[[The system of the demography of the aged]].
D000328:Adult; D000367:Age Factors; D000368:Aged; D003710:Demography; D011153:Population; D011154:Population Characteristics; D011157:Population Dynamics; D012106:Research
Adult; Age Factors; Aged; Demographic Aging; Demographic Factors; Population; Population Characteristics; Population Dynamics; Research Methodology; World