1. G. Stengele, C. Hueller and X. Specht.: Proceedings of 3rd Parallel Kinematics Seminar, (Chemnitz, Germany, 2002), pp.609-612.
2. J.M. Herve: Mechanism and Machine Theory. Vol. 34 (1999), pp.719-721.
3. S. Bruno: Robotic Vol. 17. 4 (1999), pp.437-440.
4. J.M. Luo, Y. Xing, D. Wang and X.Q. Guan: 2008 IEEE International Conference on Automation and Logistics (Qingdao, China,. Sep. 3-5. 2008 ) pp.1145-1147.
5. J.M. Luo, G.Q. Cai, B.J. Yang and L. Zhao: Journal of Northeastern University (Natural Science). Vol. 126 (2005) No. 10, pp.994-997. (In Chinese).