A. Homaifar, D. Battle, and E. Tunstel. Computational Intelligence in Robotics and Automation,
CIRA '99. Proceedings. 1999 IEEE International
Symposium on, page 35--40. (8-9 November 1999)
S. Gustafson, and W. Hsu. Genetic Programming, Proceedings of EuroGP'2001, volume 2038 of LNCS, page 291--301. Lake Como, Italy, Springer-Verlag, (18-20 April 2001)