@article {2006,
	title = {Forced vibrations of wave equations with non-monotone nonlinearities},
	journal = {Ann. Inst. H. Poincar{\'e} Anal. Non Lin{\'e}aire 23 (2006) 439-474},
	number = {arXiv.org;math/0410619v1},
	year = {2006},
	abstract = {We prove existence and regularity of periodic in time solutions of completely resonant nonlinear forced wave equations with Dirichlet boundary conditions for a large class of non-monotone forcing terms. Our approach is based on a variational Lyapunov-Schmidt reduction. It turns out that the infinite dimensional bifurcation equation exhibits an intrinsic lack of compactness. We solve it via a minimization argument and a-priori estimate methods inspired to regularity theory of Rabinowitz.},
	doi = {10.1016/j.anihpc.2005.05.004},
	url = {http://hdl.handle.net/1963/2160},
	author = {Massimiliano Berti and Luca Biasco}
}
