@article{IM2_1987_29_3_a6,
     author = {A. T. Fomenko},
     title = {The topology of surfaces of constant energy in integrable {Hamiltonian} systems, and obstructions to integrability},
     journal = {Izvestiya. Mathematics },
     pages = {629--658},
     publisher = {mathdoc},
     volume = {29},
     number = {3},
     year = {1987},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1987_29_3_a6/}
}