C. Lu, S. Wu, L. Tu, and W. Hsu. ICALT'04: Proc. 4th Int'l Conf. on Advanced
Learning Technologies, page 525--529. Joensuu, Finland, IEEE Press, (2004)
C. Wang, C. Lai, C. Wu, S. Hwang, and Y. Lin. VLSI Design, Automation and Test, 2008. VLSI-DAT 2008. IEEE International Symposium on, page 25--28. (abr. 2008)
E. Shih, P. Bahl, and M. Sinclair. MobiCom '02: Proceedings of the 8th annual international conference
on Mobile computing and networking, page 160--171. New York, NY, USA, ACM, (2002)