@misc{AiriauEtAlSIGECOM2009,
  author =        {St\'ephane Airiau and Ulle Endriss and Joseph Y. Halpern},
  title =         {Solution to Exchanges 8.1 Puzzle: Identifying the Champion},
  month =         {December},
  year =          {2009},
  howpublished =  {ACM SIGecom Exchanges, Vol.~8, No.~2}
}