Guo-Shi Li Xavier Tricoche Daniel Weiskopf Charles D. Hansen Flow Charts: Visualization of Vector Fields on Arbitrary Surfaces. 1067-1080 2008 14 IEEE Trans. Vis. Comput. Graph. 5 http://doi.ieeecomputersociety.org/10.1109/TVCG.2008.58 db/journals/tvcg/tvcg14.html#LiTWH08