Panayiotis Andreou Demetrios Zeinalipour-Yazti Panos K. Chrysanthis George Samaras Workload-Aware Query Routing Trees in Wireless Sensor Networks. 189-196 2008 MDM http://doi.ieeecomputersociety.org/10.1109/MDM.2008.13 conf/mdm/2008 db/conf/mdm/mdm2008.html#AndreouZCS08