J. Bowen, and M. Hinchey. Rigorous Methods for Software Construction and Analysis, volume 5115 of Lecture Notes in Computer Science, page 219-233. Springer, (2009)
M. Korns. Genetic Programming Theory and Practice IV, volume 5 of Genetic and Evolutionary Computation, chapter 16, Springer, Ann Arbor, (11-13 May 2006)