@article{MZM_1969_5_2_a8,
     author = {V. M. Mordashev},
     title = {Best approximations of functions of several variables by sums of functions of fewer variables},
     journal = {Matemati\v{c}eskie zametki},
     pages = {217--226},
     publisher = {mathdoc},
     volume = {5},
     number = {2},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1969_5_2_a8/}
}