[1] Bluman G W, Kumei S. Symmetries and Differential Equations [M]. New York: Springer, 1989.
[2] Bluman G W, Cheviakov A F, Anco S C. Applications of Symmetry Methods to Partial Differential Equations [M]. New York: Springer, 2010.
[3] Benjamin T B. The stability of solitary waves [J]. Proc. Roy. Soc. London A, 1972, 328: 153-183.
[4] Noether E. Invariante variations probleme [J]. Nachr. Konig. Gesell. Wissen., Gottingen, Math.-Phys. Kl. Heft, 1918, 2: 235-257.
[5] Olver P J. Application of Lie Groups to Differential Equations [M]. New York: Springer, 1993.
[6] Anco S C, Bluman G W. Direct construction method for conservation laws of partial differential equations, Part I: Examples of conservation laws classifications [J]. Eur. J. Appl. Math., 2002, 13: 545-566.
[7] Kara A H, Mahomed F M. Noether-type symmetries and conservation laws via partial Lagrangians [J]. Nonlinear Dynam., 2006, 45: 367-383.
[8] Ibragimov N H. A new conservation theorem [J]. J. Math. Anal. Appl., 2007, 333: 311-328.
[9] Ibragimov N H. Integrating factors, adjoint equations and Lagrangians [J]. J. Math. Anal. Appl., 2006, 318: 742-757.
[10] Ibragimov N H. Quasi-self-adjoint differential equations [J]. Arch. ALGA., 2007, 4: 55-60.
[11] Ibragimov N H, Torrisi M, Tracina R. Quasi self-adjoint nonlinear wave equations [J]. J. Phys. A: Math. Theor., 2011, 43: 442001.
[12] Gandarias M L. Weak self-adjoint differential equations [J]. J. Phys. A: Math. Theor., 2011, 44: 262001.
[13] Ibragimov N H, Torrisi M, et al. Self-adjointness and conservation laws of a generalized Burgers equation [J]. J. Phys. A: Math. Theor., 2011, 44: 145201.
[14] Bruzon M S, Gandarias M L, Ibragimov N H. Self-adjoint sub-classes of generalized thin film equations [J]. J. Math. Anal. Appl., 2009, 357: 307-313.
[15] Gandarias M L, Redondo M, Bruzon M S. Some weak self-adjoint Hamilton-Jacobi-Bellman equations arising in financial mathematics [J]. Nonlinear Anal. RWA, 2012, 13: 340-347.
[16] Ibragimov N H. Nonlinear self-adjointness and conservation laws [J]. J. Phys. A: Math. Theor., 2011, 44: 432002.
[17] Naz R, Mahomed F M, Mason D P. Comparison of different approaches to conservation laws for some partial differential equations in fluid mechanics [J]. Appl. Math. Com., 2008, 205: 212-230.
[20] Zhao J X, Guo B L. Analytical solutions to forced KdV equation [J]. Commun. Theor. Phys., 2009, 52: 279-283.
[21] Salas A H. Computing solutions to a forced KdV equation [J]. Nonlinear Anal. RWA, 2011, 12: 1314-1320.