%0 Journal Article
%A L. T. Ashchepkov
%A O. V. Vasiliev
%A I. L. Kovalenok
%T A strong optimality condition for singular controls in a Goursat--Darboux system
%J Differencialʹnye uravneniâ
%D 1980
%P 1054-1059
%V 16
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1980_16_6_a7/
%G ru
%F DE_1980_16_6_a7