%0 Journal Article %A Creutzig, J. %A Linde, W. %T Entropy numbers of certain summation operators. %J Georgian Mathematical Journal %D 2001 %P 245-274 %V 8 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/GMJ_2001__8_2_50859/ %G en %F GMJ_2001__8_2_50859