%0 Journal Article
%A Z. D. Usmanov
%T On~a~problem concerning the deformation of a~surface with a~flat point
%J Sbornik. Mathematics
%D 1972
%P 61-81
%V 18
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/SM_1972_18_1_a3/
%G en
%F SM_1972_18_1_a3