%0 Journal Article
%A V. A. Kozlov
%A V. A. Kondrat'ev
%A V. G. Maz'ya
%T On sign variation and the absence of ``strong'' zeros of solutions of elliptic equations
%J Izvestiya. Mathematics 
%D 1990
%P 337-353
%V 34
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/IM2_1990_34_2_a5/
%G en
%F IM2_1990_34_2_a5