L. Spector, and J. Klein. Genetic Programming Theory and Practice III, volume 9 of Genetic Programming, chapter 8, Springer, Ann Arbor, (12-14 May 2005)
F. Chapelle, and P. Bidaud. IEEE International Conference on Robotics and
Automation (ICRA'01), 4, page 3364--3369. Seoul, Korea, IEEE, (21-28 May 2001)