@article{RLIN_2002_9_13_2_a1,
     author = {Berti, Massimiliano and Biasco, Luca and Bolle, Philippe},
     title = {Optimal stability and instability results for a class of nearly integrable {Hamiltonian} systems},
     journal = {Atti della Accademia nazionale dei Lincei. Rendiconti Lincei. Matematica e applicazioni},
     pages = {77--84},
     publisher = {mathdoc},
     volume = {Ser. 9, 13},
     number = {2},
     year = {2002},
     zbl = {1072.37060},
     mrnumber = {1614571},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RLIN_2002_9_13_2_a1/}
}