Computer Algebra and Geometric Algebra with Applications 6th International Workshop, IWMM 2004, Shanghai, China, May 19-21, 2004 and International Workshop, GIAE 2004, Xian, China, May 24-28, 2004, Revised Selected Papers - Li, Hongbo; Olver, Peter J.; Sommer, Gerald (Springer Berlin Heidelberg, 2005)