@article{MM2_1992__75_4_155722,
     author = {G. Dal Maso and Anneliese Defranceschi},
     title = {A characterization of {C1-convex} sets in {Sobolev} spaces.},
     journal = {Manuscripta mathematica},
     pages = {247--272},
     publisher = {mathdoc},
     volume = {75},
     number = {4},
     year = {1992},
     zbl = {0766.46014},
     url = {http://geodesic.mathdoc.fr/item/MM2_1992__75_4_155722/}
}