@article{MZM_1985_37_2_a6,
     author = {A. V. Kryazhimskii and Yu. S. Osipov},
     title = {Best approximation of the differentiation operator in the class of nonanticipatory operators},
     journal = {Matemati\v{c}eskie zametki},
     pages = {192--199},
     publisher = {mathdoc},
     volume = {37},
     number = {2},
     year = {1985},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1985_37_2_a6/}
}