@article{MZM_1980_27_4_a7,
     author = {N. N. Zaderei and A. I. Stepanets},
     title = {Approximation of {Fourier} sums on classes of periodic functions that are defined by polyharmonic operators},
     journal = {Matemati\v{c}eskie zametki},
     pages = {569--581},
     publisher = {mathdoc},
     volume = {27},
     number = {4},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1980_27_4_a7/}
}