%0 Journal Article %J Nonlinear Differential Equations and Applications %D 2008 %T Cantor families of periodic solutions of wave equations with C k nonlinearities %A Massimiliano Berti %A Philippe Bolle %X We prove bifurcation of Cantor families of periodic solutions for wave equations with nonlinearities of class C k . It requires a modified Nash-Moser iteration scheme with interpolation estimates for the inverse of the linearized operators and for the composition operators. © 2008 Birkhaueser. %B Nonlinear Differential Equations and Applications %V 15 %P 247-276 %G eng %R 10.1007/s00030-007-7025-5