%0 Journal Article
%A A. G. Kuz'min
%T Boundary value problems for equations of mixed type with characteristics that cross the line of degeneracy twice.~I
%J Differencialʹnye uravneniâ
%D 1975
%P 1853-1861
%V 11
%N 10
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1975_11_10_a16/
%G ru
%F DE_1975_11_10_a16