@article{EJDE_2002__2002__a290,
     author = {Fei,  Guihua},
     title = {On periodic solutions of superquadratic {Hamiltonian} systems},
     journal = {Electronic journal of differential equations},
     year = {2002},
     volume = {2002},
     zbl = {0999.37039},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2002__2002__a290/}
}