%0 Journal Article %A S. I. Repin %T A~posteriori estimates for the accuracy of variational methods for problems with nonconvex functionals %J Algebra i analiz %D 1999 %P 151-182 %V 11 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/AA_1999_11_4_a6/ %G ru %F AA_1999_11_4_a6