Muhammad Aamir Cheema Yidong Yuan Xuemin Lin CircularTrip: An Effective Algorithm for Continuous <i>k</i> NN Queries. 863-869 2007 conf/dasfaa/2007 DASFAA http://dx.doi.org/10.1007/978-3-540-71703-4_71 db/conf/dasfaa/dasfaa2007.html#CheemaYL07