@article{DAN_1987_296_1_a6,
     author = {Yu. E. Nesterov and B. V. Cherkasskii},
     title = {Lexicographic rules for the differentiation of nonsmooth},
     journal = {Doklady Akademii Nauk},
     pages = {32--34},
     publisher = {mathdoc},
     volume = {296},
     number = {1},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1987_296_1_a6/}
}