@article{DAN_1987_293_4_a5,
     author = {A. I. Stepanets},
     title = {Approximations on classes of $(\psi,\beta)$-differentiable functions},
     journal = {Doklady Akademii Nauk},
     pages = {797--800},
     publisher = {mathdoc},
     volume = {293},
     number = {4},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1987_293_4_a5/}
}