C. Ryan, M. O'Neill, and A. Azad. Proceedings of the Genetic and Evolutionary
Computation Conference (GECCO-2001), page 187. San Francisco, California, USA, Morgan Kaufmann, (7-11 July 2001)
M. Solano, and I. Jonyer. GECCO '07: Proceedings of the 9th annual conference on
Genetic and evolutionary computation, 2, page 1757--1757. London, ACM Press, (7-11 July 2007)