%0 Journal Article
%A G. A. Kovaleva
%T Example of a~surface that is homotopic to a~tube and has a~closed asymptotic line
%J Matematičeskie zametki
%D 1968
%P 403-413
%V 3
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/MZM_1968_3_4_a4/
%G ru
%F MZM_1968_3_4_a4