%0 Journal Article
%A B. V. Shabat
%T On the notion of derivative system according to M.\,A.~Lavrentʹev
%J Doklady Akademii Nauk
%D 1961
%P 1298-1301
%V 136
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1961_136_6_a9/
%G ru
%F DAN_1961_136_6_a9