%0 Journal Article
%A Nguyen Thi Thien Hoa
%T The oscillation property of the operator $D(D^2+1^2)\cdots
%J Doklady Akademii Nauk
%D 1989
%P 289-293
%V 304
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1989_304_2_a6/
%G ru
%F DAN_1989_304_2_a6