Clara M. Campos Rodríguez José A. Moreno-Pérez Hartmut Noltemeier Dolores-Rosa Santos-Peñate Two-Swarm PSO for Competitive Location Problems. 115-126 2008 NICSO http://dx.doi.org/10.1007/978-3-642-03211-0_10 conf/nicso/2008 db/conf/nicso/nicso2008.html#RodriguezMNS08