@article{MZM_1998_64_2_a15,
     author = {V. V. Belov and V. A. Maksimov},
     title = {Quasimodes of the two-dimensional quartic oscillator},
     journal = {Matemati\v{c}eskie zametki},
     pages = {297--301},
     publisher = {mathdoc},
     volume = {64},
     number = {2},
     year = {1998},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1998_64_2_a15/}
}