Andrzej Nowakowski, Andrzej Rogowski, “Wave equation in higher dimensions - periodic solutions”, Electron. J. Qual. Theory Differ. Equ., 2018, no. 103, 1
Chengming Cao, Xiaoping Yuan, “Quasi-periodic solutions for perturbed generalized nonlinear vibrating string equation with singularities”, Discrete & Continuous Dynamical Systems - A, 37:4 (2017), 1867
Hongzi Cong, Meina Gao, Jianjun Liu, “Long time stability of KAM tori for nonlinear wave equation”, Journal of Differential Equations, 2015
Jie Liu, Jianguo Si, “Invariant tori for a derivative nonlinear Schrödinger equation with quasi-periodic forcing”, J. Math. Phys, 56:3 (2015), 032702
Alejandro Luque, Jordi Villanueva, “A KAM theorem without action-angle variables for elliptic lower dimensional tori”, Nonlinearity, 24:4 (2011), 1033
Yuri B. Suris, “Integrable discretizations of the Bogoyavlensky lattices”, Journal of Mathematical Physics, 37:8 (1996), 3982
Luigi Chierchia, Paolo Perfetti, Seminar on Dynamical Systems, 1994, 203
G. R. W. Quispel, M. B. Sevryuk, “KAM theorems for the product of two involutions of different types”, Chaos, 3:4 (1993), 757
R Cirelli, L Pizzocchero, Nonlinearity, 3:4 (1990), 1057
С. Б. Куксин, “О консервативных возмущениях бесконечномерных линейных систем, зависящих от векторного параметра”, Функц. анализ и его прил., 23:1 (1989), 72–73 ; S. B. Kuksin, “Conservative perturbations of infinite-dimensional linear systems depending on a vector parameter”, Funct. Anal. Appl., 23:1 (1989), 62–63