@incollection{Fawcett73-variation,
  author	= {Fawcett, Robin P.},
  editor	= {Candlin, C. N.},
  year		= {1973},
  title		= {Language functions and language variation in a cognitive model of communication},
  booktitle	= {The communicative teaching of English},
  publisher	= {Lancaster University Press},
  address	= {Lancaster}
}