J. Samarabandu, and O. Jakubowicz. Proceedings of the International Joint Conference on Neural Networks (Washington, DC), 2, page 683--686. Hillsdale, NJ, Erlbaum, (1990)
C. Rosin, and R. Belew. CS96-491. Cognitive Computer Science Research Group, Department of Computer Science and Engineering, University of California, San Diego, La Jolla, CA, (1996)
K. Obermayer, H. Ritter, and K. Schulten. Proceedings of the International Conference on Parallel Processing in Neural Systems and Computers (ICNC), New York, Elsevier, (1990)