@inproceedings{cccg-06
, title =       "An Improved Approximation Factor For The Unit Disk Covering Problem"
, author =      "Sada Narayanappa and Petr Vojtechovsky"
, booktitle =   "Proceedings of the 18th Canadian Conference on Computational Geometry (CCCG'06)"
, site =        "Kingston"
, year =        2006
, pages =       "15--18"
}