@article{Amati:2002:TOIS,
   author =    {Gianni Amati and Cornelis Joost Van Rijsbergen},
   title =     {Probabilistic models of information retrieval based on measuring 
                the divergence from randomness},
   journal =   {ACM Transactions on Information Systems (TOIS)},
   volume =    20,
   number =    4,
   year =      2002,
   issn =      {1046-8188},
   pages =     {357--389},
   doi =       {http://doi.acm.org/10.1145/582415.582416},
   publisher = {ACM Press},
}