Nonlinear excitations: Solitons
  The main purpose of this chapter is to present a brief introduction to nonlinear excitations, and to underline the soliton concept. This chapter is Chapter 5 in the book High-Temperature Superconductivity: The Nonlinear Mechanism and Tunneling Measurements (Kluwer Academic, Dordrecht, 2002), pages 101-142. 
A. Mourachkine (Cambridge)