@article{TIMM_2012_18_2_a12,
     author = {O. M. Kiselev},
     title = {Oscillations near a~separatrix in the {Duffing} equation},
     journal = {Trudy Instituta matematiki i mehaniki},
     pages = {141--153},
     year = {2012},
     volume = {18},
     number = {2},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TIMM_2012_18_2_a12/}
}