@article{GDZPPN002323109,
title = {Periodic Solutions of a Nonlinear Wave Equation Without Assumption of Monotonicity.},
journal = {Mathematische Annalen},
volume = {264},
year = {1983},
pages = {273-286},
zbl = {0489.35061},
url = {http://dml.mathdoc.fr/item/GDZPPN002323109}
}
Coron, J.M. Periodic Solutions of a Nonlinear Wave Equation Without Assumption of Monotonicity.. Mathematische Annalen, Tome 264 (1983) pp. 273-286. http://gdmltest.u-ga.fr/item/GDZPPN002323109/