@article{DAN_1969_186_4_a3,
     author = {M. G. Gasymov},
     title = {The distribution of eigenvalues of selfadjoint ordinary differential operators},
     journal = {Doklady Akademii Nauk},
     pages = {753--756},
     publisher = {mathdoc},
     volume = {186},
     number = {4},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1969_186_4_a3/}
}