@article{TMF_1990_82_2_a9,
     author = {I. V. Krivoshei},
     title = {Instability criterion for multidimensional nonlinear {Hamiltonian} systems},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {268--277},
     year = {1990},
     volume = {82},
     number = {2},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1990_82_2_a9/}
}