@article{SM_1981_38_1_a9,
     author = {Kh. Kh. Murtazin and T. G. Amangil'din},
     title = {The asymptotic expansion of the spectrum of {a~Sturm--Liouville} operator},
     journal = {Sbornik. Mathematics},
     pages = {127--141},
     publisher = {mathdoc},
     volume = {38},
     number = {1},
     year = {1981},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1981_38_1_a9/}
}