@article{DE_1972_8_9_a8,
     author = {Sh. A. Alimov},
     title = {Fractional powers of elliptic operators and isomorphism of classes of differentiable functions},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1609--1626},
     publisher = {mathdoc},
     volume = {8},
     number = {9},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1972_8_9_a8/}
}