Mihaela Enachescu Ashish Goel Ramesh Govindan Rajeev Motwani Scale Free Aggregation in Sensor Networks. 71-84 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3121&spage=71 2004 conf/algosensors/2004 ALGOSENSORS db/conf/algosensors/algosensors2004.html#EnachescuGGM04