@article{FPM_1997_3_3_a1,
     author = {A. S. Ambrosimov},
     title = {Approximation of $k$-ary functions by functions from the given system},
     journal = {Fundamentalʹna\^a i prikladna\^a matematika},
     pages = {653--674},
     publisher = {mathdoc},
     volume = {3},
     number = {3},
     year = {1997},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FPM_1997_3_3_a1/}
}