@article{05897649,
title = {Three solutions for forced Duffing-type equations with damping term.},
journal = {Boundary Value Problems [electronic only]},
volume = {2011},
year = {2011},
doi = {10.1155/2011/736093},
zbl = {1225.34029},
language = {en},
url = {http://dml.mathdoc.fr/item/05897649}
}
Li, Yongkun; Zhang, Tianwei. Three solutions for forced Duffing-type equations with damping term.. Boundary Value Problems [electronic only], Tome 2011 (2011) . doi : 10.1155/2011/736093. http://gdmltest.u-ga.fr/item/05897649/