@article{DAN_1980_254_3_a6,
     author = {A. I. Stepanets},
     title = {Simultaneous approximation of periodic functions and their derivatives by {Fourier} sums},
     journal = {Doklady Akademii Nauk},
     pages = {543--544},
     publisher = {mathdoc},
     volume = {254},
     number = {3},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1980_254_3_a6/}
}