@article{DE_1982_18_5_a20,
     author = {A. A. Bel'kovich},
     title = {Quasiperiodic solutions of {Hamiltonian} systems with a small parameter},
     journal = {Differencialʹnye uravneni\^a},
     pages = {886--889},
     publisher = {mathdoc},
     volume = {18},
     number = {5},
     year = {1982},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1982_18_5_a20/}
}