@article{IVM_1970_3_a6,
     author = {V. V. Lipovik},
     title = {The order of approximation in the strong sense of periodic functions of two variables by {Fourier} sums and by certain interpolation sums},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {43--49},
     publisher = {mathdoc},
     number = {3},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1970_3_a6/}
}