@article{05002684,
title = {Periodic solutions for a class of second-order Hamiltonian systems.},
journal = {Electronic Journal of Differential Equations (EJDE) [electronic only]},
volume = {2005},
year = {2005},
zbl = {1096.34027},
language = {en},
url = {http://dml.mathdoc.fr/item/05002684}
}
Bonanno, Gabriele; Livrea, Roberto. Periodic solutions for a class of second-order Hamiltonian systems.. Electronic Journal of Differential Equations (EJDE) [electronic only], Tome 2005 (2005) . http://gdmltest.u-ga.fr/item/05002684/