@incollection{DonnellySmith2003-layers,
  author	= {Donnelly, Maureen and Smith, Barry},
  editor	= {Kuhn, W. and Worboys, M. F. and Timpf, S.},
  URL		= {http://ontology.buffalo.edu/geo/Layers.pdf},
  pdf		= {http://ontology.buffalo.edu/geo/Layers.pdf},
  title		= {Layers: A New Approach to Locating Objects in Space},
  booktitle	= {Spatial Information Theory: Foundations of Geographic Information Science},
  series	= {Lecture Notes in Computer Science},
  number	= {2825},
  publisher	= {Springer},
  address	= {Berlin},
  year		= {2003},
  pages		= {50--65}
}