Crystal cells in geometric algebra
 @InProceedings{hitzer04isame,
  author = 	 {E. Hitzer and C. Perwass},
  title = 	 {Crystall cells in geometric algebra},
  booktitle =	 {Proceedings of International Symposium on Advanced Mechanical Engineering, November 2004, Fukui, Japan },
  pages =	 {290-295},
  year =	 2004,
  publisher =	 {Department of Mechanical Engineering, University of Fukui, Japan}
}