@incollection{Keenan71,
  author	= {Keenan, E. L.},
  editor	= {Fillmore, C. J. and Langendoen, D. T.},
  year		= {1971},
  title		= {Two Kinds of Presuppositions in Natural Language},
  booktitle	= {Studies in Linguistic Semantics},
  publisher	= {Holt, Rinehart, and Winston},
  address	= {New York}
}