@article{ZVMMF_1966_6_14_a4,
     author = {S. I. Khudyaev},
     title = {Certain estimates of the eigenvalues for spherically symmetric problems},
     journal = {\v{Z}urnal vy\v{c}islitelʹnoj matematiki i matemati\v{c}eskoj fiziki},
     pages = {68--74},
     publisher = {mathdoc},
     volume = {6},
     number = {14},
     year = {1966},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZVMMF_1966_6_14_a4/}
}