%0 Journal Article %A B. Bollobas %A E. Galanis %T An Inequality Involving a Hermitian Operator and its Square in a Normed Space %J Μαθηματική Επιθεώρηση %D 1980 %P 44-49 %V 17 %I mathdoc %U http://geodesic.mathdoc.fr/item/MR_1980__17_a6/ %G gr %F MR_1980__17_a6