@article{IVM_1968_1_a5,
     author = {O. D. Gabisoniya},
     title = {The magnitude of the best approximation of a~function of several variables by means of polynomials in {Haar} functions},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {39--46},
     publisher = {mathdoc},
     number = {1},
     year = {1968},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1968_1_a5/}
}