@article{TMF_1979_41_3_a4,
     author = {P. A. Braun},
     title = {Quasienergies of an anharmonic oscillator in parametric resonance},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {336--345},
     publisher = {mathdoc},
     volume = {41},
     number = {3},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1979_41_3_a4/}
}