@article{ZLK08,

    author    = "Cai-Nicolas Ziegler and Georg Lausen and Joseph Konstan",
    title     = "On Exploiting Classification Taxonomies in Recommender Systems",
    journal   = "AI Communications",
    volume    = "21",
    number    = "2-3",
    publisher = "Elsevier Science",
    pages     = "97--125",
    year      = "2008"
}