@TechReport{roberts02b,
  author =       "Andrew Roberts and Eric Atwell",
  title =        "Unsupervised grammar inference systems for natural
                 language",
  institution =  "School of Computing, University of Leeds",
  year =         "2002",
  number =       "2002.20",
  url =          "http://www.comp.leeds.ac.uk/andyr/research/papers/roberts_techreport2002_20.pdf"
}