@article{DAN_1965_163_4_a10,
     author = {I. N. Pak},
     title = {Properties of the sums of certain sine and cosine series},
     journal = {Doklady Akademii Nauk},
     pages = {827--829},
     year = {1965},
     volume = {163},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1965_163_4_a10/}
}