J. Busch, и W. Banzhaf. Proceedings, Fourth International Conference on MultiAgent Systems, стр. 371--372. Boston, MA, USA, IEEE Computer Society, (июля 2000)
W. Fontana. Proc. Workshop on Artificial Life (ALIFE '90), том 5 из Santa Fe Institute Studies in the Sciences of, стр. 159--210. Redwood City, CA, USA, Addison-Wesley, (1992)