Suxin Wang Leizhen Wang Huilin Yuan Meng Ge Ben Niu Weihong Pang Yuchuan Liu Study on Multi-Depots Vehicle Scheduling Problem and Its Two-Phase Particle Swarm Optimization. 748-756 2009 ICIC (2) http://dx.doi.org/10.1007/978-3-642-04020-7_80 conf/icic/2009-2 db/conf/icic/icic2009-2.html#WangWYGNPL09