%0 Journal Article
%A A. Dzhuraev
%T Systems of second order partial differential equations of composite type with one double family of real characteristics
%J Doklady Akademii Nauk
%D 1969
%P 761-764
%V 186
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1969_186_4_a5/
%G ru
%F DAN_1969_186_4_a5