7Cowgill, P. 1974, Aging and Modernization: A Revision of Theory, In J, Gubrium (Ed,) ,later life: Community and Environmental Policies(pp, 123- 146),New York: Free Press.
8Cowgill, P. 1974, Aging and Modernization: A Revision of Theory, In J, Gubrium (Ed.) ,later llfe: Community and Enviromaaental Policies(pp, 123 - 146) ,New York: Free Press.
9Du P and P Tu 2000 Population Aging and Old Security . The Changing Population of China , Blackwell Publishers.
10Scott Rozelle, L G ,Minggao Shen, et al 1999 . Leaving China' s Farms: Survey Results of New Paths and Remaining Hurdles to Rural Migration ." Tne China Quartedy.
