7Bulmer M. The Social Basis of Community Care[M].London:Allen and Unwin,1987.108-115.
8Froland C, Pancoast DL, Chapman NZ, et al. Linking Formal and Informal Support Systems[A].in:Gottliet BH. eds. Social Network and Social Support[C].London:Sage Publication,1981.259-275.
9Germain CB, Gitterman A. Ecological Perspective[A].in:Edwards RL. eds. Encyclopedia of Social Work[C].19th edition.Washington DC:NASW,1996.816-823.
