@InProceedings{ShokouhiAT09,
  author = 	 {Milad Shokouhi and Leif Azzopardi and Paul Thomas},
  title = 	 {Effective query expansion for federated search},
  booktitle =    {Proceedings of ACM SIGIR},
  location =     {Boston, USA},
  year = 	 {2009},
  note =         {\url{http://es.csiro.au/pubs/shokouhi_sigir09.pdf}}
}