Yunjun Gao Jiacheng Yang Gang Chen 0001 Baihua Zheng Chun Chen On efficient obstructed reverse nearest neighbor query processing. 191-200 2011 GIS http://doi.acm.org/10.1145/2093973.2094000 conf/gis/2011 db/conf/gis/gis2011.html#GaoYCZC11