J. Wichard, and M. Ogorzalek. Proceedings of the IEEE International Joint Conference on Neural Networks., page 1625-1630. Budapeste, Hungria, (July 2004)
S. Wesolkowski, and K. Hassanein. Proceedings of the IEEE International Conference on Systems, Man, and Cybernetics., page 3534-3539. Orlando, EUA, (Outubro 1997)