Evanthia Papadopoulou On the Hausdorff Voronoi Diagram of Point Clusters in the Plane. 439-450 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2748&spage=439 2003 conf/wads/2003 WADS db/conf/wads/wads2003.html#Papadopoulou03