%0 Journal Article
%A D. Kh. Safarov
%T Systems of first-order partial differential equations of composite type
%J Differencialʹnye uravneniâ
%D 1985
%P 272-276
%V 21
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1985_21_2_a10/
%G ru
%F DE_1985_21_2_a10