@article{VSPUI_2014_1_a4,
     author = {V. V. Zhuk and O. A. Tumka},
     title = {On some modifications of {Jackson's} generalized theorem for the best approximations of periodic functions},
     journal = {Vestnik Sankt-Peterburgskogo universiteta. Prikladna\^a matematika, informatika, processy upravleni\^a},
     pages = {40--50},
     publisher = {mathdoc},
     number = {1},
     year = {2014},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VSPUI_2014_1_a4/}
}