@article{Halliday69,
  author	= {Halliday, Michael A. K.},
  year		= {1969},
  title		= {Options and functions in the English clause},
  journal	= {Brno Studies in English},
  volume	= {8},
  pages		= {82--88},
  note		= {Reprinted in Halliday and Martin (eds.)(1981) \em Readings in Systemic Linguistics, Batsford, London}
}