@ARTICLE\{IMM2001-02084,
    author       = "P. Fischer and J. Matousek",
    title        = "A lower bound for families of Natarajan dimension d",
    year         = "2001",
    pages        = "189-195",
    journal      = "Journal of Combinatorial Theory, Series A",
    volume       = "95",
    editor       = "",
    number       = "",
    publisher    = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/2084-full.html"
}