@article{MZM_1999_65_3_a0,
     author = {Yu. N. Bibikov},
     title = {Stability and bifurcation under periodic perturbations of the equilibrium position of an oscillator with an infinitely large or infinitely small oscillation frequency},
     journal = {Matemati\v{c}eskie zametki},
     pages = {323--335},
     publisher = {mathdoc},
     volume = {65},
     number = {3},
     year = {1999},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1999_65_3_a0/}
}