%0 Journal Article
%A I. V. Mustyatsa
%T Union of derivative chains of two quadratic pencils of unbounded operators
%J Matematičeskie zametki
%D 1992
%P 85-90
%V 51
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/MZM_1992_51_4_a10/
%G ru
%F MZM_1992_51_4_a10