Ant Colony Optimization and Swarm Intelligence 5th International Workshop, ANTS 2006, Brussels, Belgium, September 4-7, 2006. Proceedings - Dorigo, Marco; Gambardella, Luca Maria; Birattari, Mauro; Martinoli, Alcherio; Poli, Riccardo; Stützle, Thomas (Springer Berlin Heidelberg, 2006)