%0 Journal Article
%A N. A. Izobov
%A A. S. Platonov
%T On the existence of a linear Pfaffian system with a disconnected lower characteristic set of positive measure
%J Differencialʹnye uravneniâ
%D 1999
%P 65-71
%V 35
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1999_35_1_a9/
%G ru
%F DE_1999_35_1_a9