%0 Journal Article %A Ya. Z. Tsypkin %T An estimate of the degree of stability of non-linear sample-data systems %J Doklady Akademii Nauk %D 1964 %P 1272-1273 %V 155 %N 6 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1964_155_6_a8/ %G ru %F DAN_1964_155_6_a8