%0 Journal Article %A G. Carlier %T A Necessary and Sufficient Optimality Condition for a Class of Nonconvex Scalar Variational Problems %J Journal of convex analysis %D 2004 %P 401-411 %V 11 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/JCA_2004_11_2_JCA_2004_11_2_a8/ %F JCA_2004_11_2_JCA_2004_11_2_a8