@article{05312504,
title = {Existence theorems of periodic solutions for second-order nonlinear difference equations.},
journal = {Advances in Difference Equations [electronic only]},
volume = {2008},
year = {2008},
doi = {10.1155/2008/247071},
zbl = {1146.39006},
language = {en},
url = {http://dml.mathdoc.fr/item/05312504}
}
Cai, Xiaochun; Yu, Jianshe. Existence theorems of periodic solutions for second-order nonlinear difference equations.. Advances in Difference Equations [electronic only], Tome 2008 (2008) . doi : 10.1155/2008/247071. http://gdmltest.u-ga.fr/item/05312504/