1. Almost everywhere existence of the second differential of a convex function and some properties of convex surfaces connected with it;Aleksandrov;Učen. Zap. Leningr. Gos. Univ. Ser. Mat. Nauk,1939
2. Die innere Geometrie der konvexen Flächen (Goz. Izdat. Tehn. Teor. Lit., Moscow–Leningrad);Aleksandrov,1948
3. Convex functions and upper semi-continuous collections;Anderson;Duke Math. J.,1952
4. Frechet differentiability of convex functions;Asplund;Acta Math.,1968
5. Differentiability of the metric projection in finite-dimensional Euclidean space;Asplund;Proc. Amer. Math. Soc.,1973