@TechReport{	  Zumbusch:1996,
  author	= {G. W. Zumbusch},
  title		= {Multigrid methods in {D}iffpack},
  institution	= {Sintef Applied Mathematics},
  year		= {1996},
  number	= {STF42 F96016},
  address	= {Oslo, Norway},
  ps		= {http://wissrech.ins.uni-bonn.de/research/pub/zumbusch/mg.ps.gz}
		  ,
  pdf		= {http://wissrech.ins.uni-bonn.de/research/pub/zumbusch/mg.pdf}
		  ,
  annote	= {unrefereed},
  abstract	= {The report gives an introduction to the multigrid
		  iterative solvers in Diffpack. It is meant as a tutorial
		  for the use of iterative solvers, preconditioners and
		  nonlinear solvers based on multigrid methods. The first
		  steps towards this efficient equation solvers are guided by
		  a couple of examples and exercises. Since multigrid is a
		  recipe to construct solution algorithms rather than
		  black-box algorithms itself, there is lots of freedom for
		  the user to tailor the actual solver. Reflecting this fact
		  there are lots of possibilities to use the appropriate
		  classes in Diffpack. Hence there is much advice needed not
		  to get started, but also to use the methods efficiently.
		  The exercises are meant to give some experience needed for
		  applications and questions not covered in this introductory
		  report.}
}