H. Subramanian, S. Ramamoorthy, P. Stone, and B. Kuipers. GECCO 2006: Proceedings of the 8th annual conference
on Genetic and evolutionary computation, 2, page 1777--1784. Seattle, Washington, USA, ACM Press, (8-12 July 2006)
W. Langdon, S. Barrett, and B. Buxton. Proceedings of the 2003 Congress on Evolutionary
Computation CEC2003, page 807--814. Canberra, IEEE Press, (8-12 December 2003)
J. van Hemert, and M. Jansen. Proceedings of the Genetic and Evolutionary
Computation Conference (GECCO-2001), page 177. San Francisco, California, USA, Morgan Kaufmann, (7-11 July 2001)
W. Langdon, and J. Nordin. Genetic Programming, Proceedings of EuroGP'2000, volume 1802 of LNCS, page 304--315. Edinburgh, Springer-Verlag, (15-16 April 2000)