Pinaki Mitra Subhas C. Nandy Efficient Computation of Rectilinear Geodesic Voronoi Neighbor in Presence of Obstacles. 76-87 1996 conf/fsttcs/1996 FSTTCS db/conf/fsttcs/fsttcs96.html#MitraN96 http://dx.doi.org/10.1007/3-540-62034-6_39