@article{10_4153_CJM_1990_027_2,
     author = {Poliquin, Ren\'e A.},
     title = {Proto-Differentiation of {Subgradient} {Set-Valued} {Mappings}},
     journal = {Canadian journal of mathematics},
     pages = {520--532},
     year = {1990},
     volume = {42},
     number = {3},
     doi = {10.4153/CJM-1990-027-2},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1990-027-2/}
}