@article{FAA_1981_15_4_a16,
     author = {N. N. Frolov},
     title = {Homeomorphism of {Hilbert} spaces induced by a differential operator},
     journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a},
     pages = {89--90},
     publisher = {mathdoc},
     volume = {15},
     number = {4},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FAA_1981_15_4_a16/}
}