1. Symmetries and differential equations;Bluman,1989
2. Direct Methods in Soliton Theory;Hirota,2004
3. Darboux Transformation and Solitons;Matveev,1991
4. Solitons; Nonlinear Evolution Equations and Inverse Scattering;Ablowitz,1991
5. The Analytical Theory of Nonlinear Differential Equations;Kudryashov,2004