@article{DAN_1979_248_2_a0,
     author = {O. D. Apyshev and M. Otelbaev},
     title = {On the spectrum of a class of binomial operators},
     journal = {Doklady Akademii Nauk},
     pages = {265--268},
     publisher = {mathdoc},
     volume = {248},
     number = {2},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1979_248_2_a0/}
}