@article{AIHPC_1993__10_6_605_0,
     author = {Long, Yiming},
     title = {The minimal period problem of classical hamiltonian systems with even potentials},
     journal = {Annales de l'I.H.P. Analyse non lin\'eaire},
     pages = {605--626},
     publisher = {Gauthier-Villars},
     volume = {10},
     number = {6},
     year = {1993},
     mrnumber = {1253604},
     zbl = {0804.58018},
     language = {en},
     url = {http://www.numdam.org/item/AIHPC_1993__10_6_605_0/}
}