Marcelo Souza Pita Fernando Buarque de Lima Neto Simulations of egoistic and altruistic behaviors using the vidya multiagent system platform. 2927-2932 2007 conf/gecco/2007c GECCO (Companion) http://doi.acm.org/10.1145/1274000.1274047 db/conf/gecco/gecco2007c.html#PitaN07