Ellson, J. ; Gansner, E.R. ; Koutsofios, E. ; North, S.C. ; Woodhull, G. ; Junger, M. (Bearb.) ; Mutzel, P. (Bearb.): Graphviz and Dynagraph -- Static and Dynamic Graph Drawing Tools In: Graph Drawing Software. Berlin/Heidelberg : Springer-Verlag, 2004 Mathematics and Visualization). - ISBN-3-540-00881-0, S. 127--148