S. Johansson. Genetic Programming 1996: Proceedings of the First
Annual Conference, page 430. Stanford University, CA, USA, MIT Press, (28--31 July 1996)
U. Johansson, T. Lofstrom, R. Konig, and L. Niklasson. Proceedings 8th International Conference on Artificial
Intelligence and Soft Computing ICAISC, volume 4029 of Lecture Notes on Artificial Intelligence (LNAI), page 613--622. Zakopane, Poland, Springer-Verlag, (June 2006)
R. Konig, U. Johansson, and L. Niklasson. 2007 IEEE Congress on Evolutionary Computation, page 1304--1310. Singapore, IEEE Computational Intelligence Society, IEEE Press, (25-28 September 2007)
U. Johansson, T. Lofstrom, R. Konig, and L. Niklasson. Proceedings of the 2006 IEEE Congress on Evolutionary
Computation, page 2239--2244. Vancouver, IEEE Press, (6-21 July 2006)