Baihua Zheng Jianliang Xu Wang-Chien Lee Dik Lun Lee Grid-partition index: a hybrid method for nearest-neighbor queries in wireless location-based services. 21-39 2006 15 VLDB J. 1 http://dx.doi.org/10.1007/s00778-004-0146-0 db/journals/vldb/vldb15.html#ZhengXLL06