@article{DE_1988_24_1_a14,
     author = {E. I. Moiseev},
     title = {Disposition of the spectrum of a boundary value problem with mixed boundary conditions},
     journal = {Differencialʹnye uravneni\^a},
     pages = {123--135},
     year = {1988},
     volume = {24},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1988_24_1_a14/}
}