On 2-Site Voronoi Diagrams under Geometric Distance Functions
  We revisit a new type of a Voronoi diagram, in which distance is measured from a point to a pair of points. We consider a few more such distance functions, based on geometric primitives, and analyze the structure and complexity of the nearest- and furthest-neighbor Voronoi diagrams of a point set with respect to these distance functions. 
Gill Barequet, Matthew T. Dickerson, David Eppstein, David   Hodorkovsky, Kira Vyatkina
cs.CG