1. Ablowitz, M.J., Ladik, J.E.: Nonlinear differential-difference equations and Fourier analysis. J. Math. Phys. 17, 1011 (1976)
2. Akhmediev, N.N., Ankiewicz, A.: Solitosns: Nonlinear Pulses and Beams. Chapman and Hall, London (1992)
3. Berman, G.P., Izrailev, F.M.: The Fermi–Pasta–Ulam problem: fifty years of progress. Chaos 15, 15104 (2005)
4. Berman, G.P., Kolovsky, A.R.: The limit of stochasticity for a one-dimensional chain of interacting oscillators. Sov. Phys. JETP 60, 1116 (1984)
5. Bogolyubov, N.N., Mitropol’skii Yu.A.: Asymptotic Methods in the Theory of Nonlinear Oscillations, Gordon & Breach, Delhi (1961)