@incollection{Cummings87,
  author	= {Cummings, Michael},
  editor	= {Steele, Ross and Threadgold, Terry},
  year		= {1987},
  title		= {SYSPRO: a computerized method for writing system networks and deriving selection expressions},
  booktitle	= {Language Topics: essays in honour of Michael Halliday},
  publisher	= {John Benjamins Publishing Co.},
  address	= {Amsterdam and Philadelphia},
  pages		= {45--64}
}