@article {81651, title = {Neighborhoods and Violent Crime: A Multilevel Study of Collective Efficacy}, journal = {Science}, volume = {277}, year = {1997}, pages = {918-924 }, url = {http://www.sciencemag.org/content/277/5328/918.full}, author = {Sampson, Robert J, Stephen Raudenbush, Felton Earls} }