%0 Journal Article
%A V. V. Velichenko
%T Problems of the invariance of discrete systems
%J Doklady Akademii Nauk
%D 1971
%P 284-287
%V 201
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1971_201_2_a6/
%G ru
%F DAN_1971_201_2_a6