@techreport{BornemannYserentant1992, author = {Folkmar A. Bornemann and Harry Yserentant}, title = {A Basic Norm Equivalence for the Theory of Multilevel Methods.}, institution = {ZIB}, address = {Takustr. 7, 14195 Berlin}, number = {SC-92-01}, language = {eng}, year = {1992} }