@incollection{Halliday93-darwin,
  author	= {Halliday, M. A. K.},
  editor	= {Halliday, M. A. K. and Martin, J. R.},
  title		= {The construction of knowledge and value in the grammar of scientific discourse: Charles Darwin's \em The Origin of the Species},
  booktitle	= {Writing Science: literacy and discoursive power},
  pages		= {86--105},
  publisher	= {The Falmer Press},
  year		= {1993},
  address	= {London}
}