@article{1993-Hofstede-LISA-D,
  author		= "Hofstede, A.H.M. ter and Proper, H.A. and Weide, Th.P. van der",
  title			= "{Formal definition of a conceptual language for the description and manipulation of information models}",
  journal		= "Information Systems",
  number		= "7",
  volume		= "18",
  month			= "October",
  year			= "1993",
  research_group	= "iris",
  pages			= "489--523",
  class			= "Journal"
}