@INPROCEEDINGS{PenVen04,
  AUTHOR =       {Paolo Penna and Carmine Ventre},
  TITLE =        {More Powerful and Simpler Cost-Sharing Methods},
  BOOKTITLE =    {2nd Workshop on Approximation and Online Algorithms (WAOA)},
  YEAR =         {2004},
  volume =       {3351},
  series =       {LNCS},
  pages =        {97-110}
}