Karim Mahrous Janine Bennett Gerik Scheuermann Bernd Hamann Kenneth I. Joy Topological Segmentation in Three-Dimensional Vector Fields. 198-205 2004 10 IEEE Trans. Vis. Comput. Graph. 2 http://csdl.computer.org/comp/trans/tg/2004/02/v0198abs.htm db/journals/tvcg/tvcg10.html#MahrousBSHJ04