@article{DE_1994_30_4_a7,
     author = {V. S. Klimov},
     title = {On boundary value problems with an even number of solutions},
     journal = {Differencialʹnye uravneni\^a},
     pages = {630--636},
     year = {1994},
     volume = {30},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1994_30_4_a7/}
}