@article{Hahn-etal99,
  author	= {Hahn, U. and Schulz, S. and Romacker, M.},
  title		= {Part-whole reasoning: A case study in medical ontology engineering},
  journal	= {IEEE Intelligent Systems},
  year		= {1999},
  volume	= {14},
  number	= {5},
  pages		= {59--67}
}