Highlights in Practical Applications of Agents and Multiagent Systems 9th International Conference on Practical Applications of Agents and Multiagent Systems - Pérez, Javier Bajo; Corchado, Juan M.; Moreno, María N.; Julián, Vicente; Mathieu, Philippe; Canada-Bago, Joaquin; Ortega, Alfonso; Caballero, Antonio Fernández (Springer Berlin Heidelberg, 2011)