A.  Bicchi, Danesi, A., Dini, G., La Porta, S., Pallottino, L., Savino, I. M., and Schiavi, R., ?Heterogeneous Wireless Multirobot System?, Robotics and Automation Magazine, IEEE, vol. 15, pp. 62?70, 2008 [Online]. Available: http://dx.doi.org/10.1109/M-RA.2007.914925