%0 Journal Article
%A É. V. Nikol'skii
%T The dynamic Fermat and Huygens principles for a second-order scalar three-dimensional equation of general type
%J Doklady Akademii Nauk
%D 1985
%P 284-289
%V 285
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1985_285_2_a5/
%G ru
%F DAN_1985_285_2_a5