@article{MM2_1992__76_1_155763,
     author = {G. Alberti and L. Ambrosio and P. Cannarsa},
     title = {On the singularities of convex functions.},
     journal = {Manuscripta mathematica},
     pages = {421--436},
     publisher = {mathdoc},
     volume = {76},
     number = {1},
     year = {1992},
     zbl = {0784.49011},
     url = {http://geodesic.mathdoc.fr/item/MM2_1992__76_1_155763/}
}