H. Cao, L. Kang, T. Guo, Y. Chen, and H. de Garis. IEEE Transactions on Systems, Man and Cybernetics --
Part B: Cybernetics, 40 (2):
351--357(April 2000)
Y. Zhang, and H. Chen. Advances in Natural Computation, Second International
Conference, ICNC 2006, Proceedings, Part I, volume 4221 of Lecture Notes in Computer Science, page 816--819. Xi'an, China, Springer, (September 2006)