@article{DAN_1981_257_4_a11,
     author = {A. G. Kusraev},
     title = {On a general method of subdifferentiation},
     journal = {Doklady Akademii Nauk},
     pages = {822--826},
     publisher = {mathdoc},
     volume = {257},
     number = {4},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1981_257_4_a11/}
}