@article{DE_1984_20_2_a3,
     author = {A. P. Vinnichenko},
     title = {The spectrum of a nonselfadjoint singular differential operator},
     journal = {Differencialʹnye uravneni\^a},
     pages = {215--219},
     publisher = {mathdoc},
     volume = {20},
     number = {2},
     year = {1984},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1984_20_2_a3/}
}