@article{DE_1970_6_5_a7,
     author = {G. V. Zhdanova},
     title = {The asymptotics of the eigenvalues of a selfadjoint second order singular operator},
     journal = {Differencialʹnye uravneni\^a},
     pages = {838--851},
     year = {1970},
     volume = {6},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1970_6_5_a7/}
}