@article{MZ_1996__223_3_174927,
     author = {Viktor L. Ginzburg},
     title = {On the existence and non-existence of closed trajectories for some {Hamiltonian} flows.},
     journal = {Mathematische Zeitschrift},
     pages = {397--410},
     publisher = {mathdoc},
     volume = {223},
     number = {3},
     year = {1996},
     zbl = {0862.58020},
     url = {http://geodesic.mathdoc.fr/item/MZ_1996__223_3_174927/}
}