@Article{ Griebel:1998, author = {M. Griebel}, title = {Adaptive Sparse Grid Multilevel Methods for elliptic {PDE}s based on finite differences}, journal = {Computing}, volume = {61}, number = {2}, pages = {151--179}, annote = {article,256C,CVD}, year = {1998}, ps = {http://wissrech.ins.uni-bonn.de/research/pub/griebel/varna.ps.gz} , pdf = {http://wissrech.ins.uni-bonn.de/research/pub/griebel/varna.pdf} } note = {also as Proceedings Large-Scale Scientific Computations of Engineering and Environmental Problems, 7. June - 11. June, 1997, Varna, Bulgaria, Notes on Numerical Fluid Mechanics 62, Vieweg-Verlag, Braunschweig, M. Griebel, O. Iliev, S. Margenov and P. Vassilevski (editors)},