7Lee. Kinship and social support of the elderly: The ease of the United States[J]. Aging andSociety, 1985,5:19-38.
8Lee, G. R. , Netzer, J. K. , &Coward, R. T.. Depression a- mong older parents :The role of intergenerational exchange[ J ]. Jour- nal of Marriage and the Family, 1995,57 : 823 - 833.