Jianhua Dai Weidong Chen Hongying Gu Yunhe Pan Particle Swarm Algorithm for Minimal Attribute Reduction of Decision Data Tables. 572-575 2006 conf/imsccs/2006-2 IMSCCS (2) http://doi.ieeecomputersociety.org/10.1109/IMSCCS.2006.249 db/conf/imsccs/imsccs2006-2.html#DaiCGP06