@article{DAN_1980_255_6_a0,
     author = {E. I. Berezhnoi},
     title = {Approximation spaces and interpolation},
     journal = {Doklady Akademii Nauk},
     pages = {1289--1291},
     publisher = {mathdoc},
     volume = {255},
     number = {6},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1980_255_6_a0/}
}