@article{SM_1994_77_2_a4,
     author = {A. S. Belov},
     title = {On upper estimates of the~partial sums of a~trigonometric series in terms of lower estimates},
     journal = {Sbornik. Mathematics},
     pages = {313--330},
     year = {1994},
     volume = {77},
     number = {2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1994_77_2_a4/}
}