@incollection{McGregor92-circumstantials,
  author	= {McGregor, William},
  editor	= {Davies, Martin and Ravelli, Louise},
  year		= {1992},
  title		= {The place of circumstantials in systemic-functional grammar},
  booktitle	= {Advances in systemic linguistics: recent theory and practice},
  publisher	= {Pinter},
  address	= {London},
  pages		= {136--150}
}