@INPROCEEDINGS {VSl93,
   ANNOTE = {MR94g:65048},
AUTHOR    = "{van der Vorst}, H. A. and Sleijpen, G. L. G.", 
TITLE     = "The effect of incomplete decomposition preconditioning 
             on the convergence of Conjugate Gradients",
BOOKTITLE = "Incomplete Decompositions (${\rm ILU}$)---algorithms, Theory, 
             and Applications (Kiel, 1992)",
EDITOR    = "Hackbusch, W. and Wittum, G.",
SERIES    = "Notes on Numerical Fluid Mechanics", 
VOLUME    = "41", 
PAGES     = "179--187",
PUBLISHER = "Vieweg", 
ADDRESS   = "Braunschweig", 
YEAR      = 1993,}