@article{DE_1972_8_7_a7,
     author = {R. A. Shirikyan},
     title = {The spectrum of nonselfadjoint ordinary differential operators of higher order},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1214--1224},
     publisher = {mathdoc},
     volume = {8},
     number = {7},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1972_8_7_a7/}
}