@CONFERENCE\{IMM2003-04453,
    author       = "I. L. G{\o}rtz and A. Wirth",
    title        = "Asymmetry in k-Center Variants",
    year         = "2003",
    month        = "aug",
    booktitle    = "Proc. 6th Int. Workshop on Approximation Algorithms for Combinatorial Optimization Problem. Lecture Notes in Computer Science",
    volume       = "2764",
    series       = "",
    editor       = "",
    publisher    = "Springer",
    organization = "",
    address      = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/4453-full.html"
}