%0 Journal Article
%A S. J. Bilchev
%T Systems of two first order partial differential equations (local theory)
%J Izvestiâ vysših učebnyh zavedenij. Matematika
%D 1970
%P 14-21
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/IVM_1970_3_a2/
%G ru
%F IVM_1970_3_a2