@Book{manning2008,
  author = {Manning, C. D. and Raghavan, P. and Schütze, H.},
  title  = {Introduction to Information Retrieval},

  year   = {2008},
  number = {},
  url    = {http://www-csli.stanford.edu/~hinrich/information-retrieval-book.html},

  const  = {\ text}
}
@Book{manning1999foundations,
  author = {Manning, C. and Sch\"utze, H.},
  title  = {Foundations of statistical natural language processing},

  year   = {1999},
  number = {},
  url    = {},

  const  = {\ text}
}
@Book{manning1999fsn,
  author = {Manning, C.D. and Sch{\"u}tze, H.},
  title  = {Foundations of statistical natural language processing},

  year   = {1999},
  number = {},
  url    = {},

  const  = {\ text}
}