%0 Journal Article %A Grigorios Tsagas %T On the Surfaces Whose Normal Bundles Have Special Properties %J Μαθηματική Επιθεώρηση %D 1979 %P 59-67 %V 15 %I mathdoc %U http://geodesic.mathdoc.fr/item/MR_1979__15_a15/ %G gr %F MR_1979__15_a15