@incollection{Kass89,
  author	= {Kass, Robert},
  editor	= {Kobsa, Alfred and Wahlster, Wolfgang},
  year		= {1989},
  title		= {Student modeling in Intelligent Tutoring Systems -- Implications for user modeling},
  pages		= {386--410},
  booktitle	= {User Models in Dialog Systems},
  publisher	= {Springer Verlag, Symbolic Computation Series},
  address	= {Berlin Heidelberg New York Tokyo}
}