Geir Agnarsson Peter Damaschke Magnús M. Halldórsson Powers of Geometric Intersection Graphs and Dispersion Algorithms. 140-149 2002 conf/swat/2002 SWAT http://dx.doi.org/10.1007/3-540-45471-3_15 db/conf/swat/swat2002.html#AgnarssonDH02