@article{SM_1973_21_2_a5,
     author = {A. S. Nemirovskii and S. M. Semenov},
     title = {On~polynomial approximation of functions on {Hilbert} space},
     journal = {Sbornik. Mathematics},
     pages = {255--277},
     publisher = {mathdoc},
     volume = {21},
     number = {2},
     year = {1973},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1973_21_2_a5/}
}