@Article{DorDicGam99-alife, 
  author = 	 "M. Dorigo and G. {Di Caro} and L. M. Gambardella",
  title = 	 "Ant Algorithms for Discrete Optimization",
  journal =      "Artificial Life",
  year =         "1999}",
  volume =       "5",
  number =       "2",
  pages =        "137--172"
}