R. Poli, W. Langdon, and N. McPhee. Published via http://lulu.com and freely
available at
http://www.gp-field-guide.org.uk, (2008)(With contributions by J. R. Koza).
D. Doherty, and C. O'Riordan. GECCO '07: Proceedings of the 9th annual conference on
Genetic and evolutionary computation, 2, page 1951--1958. London, ACM Press, (7-11 July 2007)
M. Tomassini, L. Vanneschi, F. Fernandez, and G. Galeano. Evolution Artificielle, 6th International Conference, volume 2936 of Lecture Notes in Computer Science, page 243--255. Marseilles, France, Springer, (27-30 October 2003)Revised Selected Papers.