%0 Journal Article
%A È. G. Poznyak
%T On second-order non-rigidity
%J Trudy Matematicheskogo Instituta imeni V.A. Steklova
%D 1961
%V 16
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/RM_1961_16_1_a12/
%G ru
%F RM_1961_16_1_a12