@Techreport{KoutsofiosNorth:2002, author= "D. Dobkin and J. Ellson and E. Gansner and E. Koutsofios and S. North and G. Woodhull", title= "Graphviz - Graph Drawing Programs", institution= "AT\&T Research and Lucent Bell Labs", note = "http://www.graphviz.org/", year= "2002"}