2Carter H. Land uses and soeial areas:19 centrury change in the small town [ J ]. Transaetion of the Institute of British Geographers, 1979 ( 1 ) :63.
3Whitehand J W R. Urban fringe belts:development of an idear [ J ]. Planning Perspetive, 1988 (3) :47.
4Berkman L F, Syme L. Social networks, host resistance, and mortality: a nine-year follow-up study of Alameda County residents [ J ]. American Journal of Epidemiology, 1979(109) :186.
5Cohen S, Doyle W J, Skoner D, et al. Social ties and sus- ceptibility to the common cold [ J ]. Journal of the Ameri- can Medical Association, 1997 (277) : 1940.
6Mehra A, Kilduff M, Brass D J. The social networks of high and low self-monitors : implications for workplace per- formance [ J ]. Administrative Science Quarterly, 2001 (35) :121.