1. G. Rebbi and G. Soliani (1984), Solitons and Particles, World Scientific Publishing, Singapore.
2. R. K. Dodd, J. C. Eilbeck, J. O. Gibbon and H. C. Morris (1982), Solitons and Nonlinear Wave Equations, Chapter 8, Academic Press, New York.
3. A. Bishop and T. Schneider (1978), Solitons and Condensed Matter Physics, Springer-Verlag, New York.
4. A. Barone, F. Esposito, C. J. Magee and A. C. Scott (1971), Theory and applications of the sine-Gordon equation, Rivista Del Nuovo Cimento 1, 227–267.
5. L. F. Mollenauer and R.H. Stolen (1982), Solitons in optical fibers, Fiberoptic Technology, April, 1982, 193–198.