@InProceedings{ThomasHJ11,
  author =       {Paul Thomas and David Hawking and Timothy Jones},
  title =        {What deliberately degrading search quality tells us about discount functions},
  booktitle = {Proceedings of ACM SIGIR 2011},
  year =      {2011},  
  location = 	 {Beijing},
  note =      {\url{http://david-hawking.net/pubs/thomas_sigir11.pdf}}
}