%0 Journal Article
%A A. B. Shvartsburg
%T Transition lines and singular points in nonlinear geometric optics equations
%J Doklady Akademii Nauk
%D 1971
%P 575-578
%V 200
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1971_200_3_a18/
%G ru
%F DAN_1971_200_3_a18