%0 Journal Article %A P. Vojčák %T A Characterization of Hyers--Lang Differentiability in Terms of a Tangent Cone %J Matematičeskie zametki %D 2011 %P 214-225 %V 89 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/MZM_2011_89_2_a4/ %G ru %F MZM_2011_89_2_a4