@article{DE_1997_33_1_a6,
     author = {P. E. Zhidkov},
     title = {On the eigenvalue problem for the {Sturm{\textendash}Liouville} operator with a potential that depends on the spectral parameter},
     journal = {Differencialʹnye uravneni\^a},
     pages = {39--47},
     year = {1997},
     volume = {33},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1997_33_1_a6/}
}