@article{05237456,
title = {Multiple periodic solutions to nonlinear discrete Hamiltonian systems.},
journal = {Advances in Difference Equations [electronic only]},
volume = {2007},
year = {2007},
doi = {10.1155/2007/41830},
zbl = {1152.39013},
language = {en},
url = {http://dml.mathdoc.fr/item/05237456}
}
Zheng, Bo. Multiple periodic solutions to nonlinear discrete Hamiltonian systems.. Advances in Difference Equations [electronic only], Tome 2007 (2007) . doi : 10.1155/2007/41830. http://gdmltest.u-ga.fr/item/05237456/