@article{DE_1988_24_8_a21,
     author = {E. V. Voskresenskii},
     title = {Sharpening of a theorem of {Levinson}},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1455--1457},
     publisher = {mathdoc},
     volume = {24},
     number = {8},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1988_24_8_a21/}
}