Yu-Ling Hsueh Roger Zimmermann Meng-Han Yang Approximate Continuous K Nearest Neighbor Queries for Continuous Moving Objects with Pre-defined Paths. 270-279 2005 conf/er/2005w ER (Workshops) http://dx.doi.org/10.1007/11568346_29 db/conf/er/erw2005.html#HsuehZY05