@article{IVM_1977_6_a5,
     author = {G. Kh. Kirov and P. D. Proinov},
     title = {The approximation of functions of several variables by trigonometric polynomials},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {50--54},
     publisher = {mathdoc},
     number = {6},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1977_6_a5/}
}