@article{DAN_1976_228_3_a1,
     author = {V. I. Burenkov and B. L. Fain},
     title = {On the extension of functions from anisotropic spaces with preservation of class},
     journal = {Doklady Akademii Nauk},
     pages = {525--528},
     publisher = {mathdoc},
     volume = {228},
     number = {3},
     year = {1976},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1976_228_3_a1/}
}