%0 Journal Article %A V. Zh. Dumanyan %T On the estimation of $\int|\nabla u|^2dx$ for solutions of second order elliptic equations %J Proceedings of the Yerevan State University. Physical and mathematical sciences %D 2008 %P 145-147 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/UZERU_2008_2_a12/ %G ru %F UZERU_2008_2_a12