References

[1] R.K.Dodd, J.C.Eilbeck, J.D.Gibbon, H.C.Morries, Solitons and Nonlinear Wave Equations (Academic Press, London, 1982).

[2] S.V.Dmitriev, T.Shigenari, A.A.Vasiliev, A.E.Miroshnichenko, Effect of discreteness on a sine-Gordon three-soliton solution // Phys.Lett. A 246 (1998) 129-134.