@article{IM2_1969_3_1_a3,
     author = {\`E. A. Storozhenko},
     title = {On the order of approximation by {Fej\'er} sums},
     journal = {Izvestiya. Mathematics },
     pages = {37--49},
     publisher = {mathdoc},
     volume = {3},
     number = {1},
     year = {1969},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1969_3_1_a3/}
}