M. Garzon, R. Deaton, L. Nino, E. Stevens, and M. Wittner. Genetic Programming 1998: Proceedings of the Third
Annual Conference, page 684--690. University of Wisconsin, Madison, Wisconsin, USA, Morgan Kaufmann, (22-25 July 1998)
L. Landweber, and L. Kari. Genetic Programming 1998: Proceedings of the Third
Annual Conference, page 700--708. University of Wisconsin, Madison, Wisconsin, USA, Morgan Kaufmann, (22-25 July 1998)