S. Mabu, Y. Chen, K. Hirasawa, and J. Hu. GECCO '07: Proceedings of the 9th annual conference on
Genetic and evolutionary computation, 2, page 2263--2263. London, ACM Press, (7-11 July 2007)
C. Yeh, and S. Chen. Proceedings of the Genetic and Evolutionary
Computation Conference (GECCO-2001), page 191. San Francisco, California, USA, Morgan Kaufmann, (7-11 July 2001)