@InProceedings{	  Griebel.Knapek:1997,
  author	= {M.~Griebel and S.~Knapek},
  title		= {A multigrid-homogenization method},
  booktitle	= {Modeling and Computation in Environmental Sciences},
  optcrossref	= {},
  optkey	= {},
  pages		= {187--202},
  year		= {1997},
  editor	= {R.~Helmig and W.~J\"ager and W.~Kinzelbach and P.~Knabner
		  and G.~Wittum},
  volume	= {59},
  optnumber	= {},
  series	= {Notes on Numerical Fluid Mechanics},
  address	= {Braunschweig},
  optmonth	= {},
  optorganization={},
  publisher	= {Vieweg-Verlag},
  optnote	= {},
  annote	= {unrefereed series}
}