Adaptive nearest neighbor queries in travel time networks. - Wei-Shinn Ku; Roger Zimmermann; Haojun Wang; Chi-Ngai Wan (GIS, 2005)

MAPLE: A Mobile Scalable P2P Nearest Neighbor Query System for Location-based Services. - Wei-Shinn Ku; Roger Zimmermann; Chi-Ngai Wan; Haojun Wang (ICDE, 2006)