@article{DAN_1966_171_5_a0,
     author = {M. Sh. Birman and M. Z. Solomyak},
     title = {Approximation of functions of the $W_p^\alpha$-classes by piece-wise-polynomial functions},
     journal = {Doklady Akademii Nauk},
     pages = {1015--1018},
     publisher = {mathdoc},
     volume = {171},
     number = {5},
     year = {1966},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1966_171_5_a0/}
}