@article{ZL05,

    author    = "Cai-Nicolas Ziegler and Georg Lausen",
    title     = "Propagation Models for Trust and Distrust in Social Networks",
    journal   = "Information Systems Frontiers",
    volume    = "7",
    number    = "4-5",
    publisher = "Springer-Verlag",
    pages     = "337--358",
    year      = "2005"
}