@article {IOPORT.50101940,
    author       = {Zhu, Hanhong and Wang, Yi and Wang, Kesheng and Chen, Yun},
    title        = {Particle swarm optimization (PSO) for the constrained portfolio optimization problem},
    year         = {2011},
    journal      = {Expert Syst. Appl.},
    volume       = {38},
    number       = {8},
    pages        = {10161-10169},
    doi          = {10.1016/j.eswa.2011.02.075},
    identifier   = {50101940},
}