M. Jünger, P. Mutzel: "Graph Drawing Software, Introduction"; in: "Graph Drawing Software", M. Jünger, P. Mutzel (ed.); Springer, 2003, ISBN: 3-540-00881-0, 1 - 7.
http://aleph.ub.tuwien.ac.at/F?base=tuw01&func=find-c&ccl_term=AC04404587