@article{DE_1996_32_12_a1,
     author = {Yu. N. Bibikov},
     title = {Quasiperiodic perturbations of an oscillator with a cubic restorative force},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1593--1598},
     publisher = {mathdoc},
     volume = {32},
     number = {12},
     year = {1996},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1996_32_12_a1/}
}