@article{TM_1997_219_a9,
     author = {V. N. Gabushin},
     title = {On {Optimal} {Recovery} of {Differentiation} {Operator}},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {125--129},
     year = {1997},
     volume = {219},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_1997_219_a9/}
}