%0 Journal Article
%A B. B. Kadomtsev
%T The invariance principle for a homogeneous medium of arbitrary shape
%J Doklady Akademii Nauk
%D 1957
%P 831-834
%V 112
%N 5
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1957_112_5_a13/
%G ru
%F DAN_1957_112_5_a13