@inbook {IOPORT.05764844,
    author       = {Erlebach, Thomas and van Leeuwen, Erik Jan},
    title        = {Approximating geometric coverage problems.},
    year         = {2008},
    booktitle    = {Proceedings of the nineteenth annual ACM-SIAM symposium on discrete algorithms (SODA 2008), San Francisco, CA, January 20--22, 2008},
    isbn         = {978-0-898716-47-4},
    pages        = {1267-1276},
    publisher    = {New York, NY: Association for Computing Machinery (ACM); Philadelphia, PA: Society for Industrial and Applied Mathematics (SIAM)},
    identifier   = {05764844},
}