@article{SM_2013_204_5_a2,
     author = {A. G. Medvedev},
     title = {Hyperbolic tori in {Hamiltonian} systems with slowly varying parameter},
     journal = {Sbornik. Mathematics},
     pages = {661--682},
     year = {2013},
     volume = {204},
     number = {5},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2013_204_5_a2/}
}