@article{RM_1970_25_4_a15,
     author = {A. D. Ioffe},
     title = {Subdifferentials of restrictions of convex functions},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     year = {1970},
     volume = {25},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/RM_1970_25_4_a15/}
}