L. Spector. Proceedings of the Genetic and Evolutionary
Computation Conference (GECCO-2001), page 137--146. San Francisco, California, USA, Morgan Kaufmann, (7-11 July 2001)
L. Spector, J. Klein, and M. Keijzer. GECCO 2005: Proceedings of the 2005 conference on
Genetic and evolutionary computation, 2, page 1689--1696. Washington DC, USA, ACM Press, (25-29 June 2005)