1. J.H. Marburger in Progress in Quantum Electronics, 4, 35–110 (1975); Y.R. Shen in the same volume.
2. G.P. Agrawal, Nonlinear Fiber Optics (Academic Press, Inc., 1989).
3. A.C. Newell and J.V. Moloney, Nonlinear Optics (Addison-Wesley, 1992).
4. E.A Kuznetsov, A.M. Rubenchik, and V.E. Zakharov, Phys. Rep., 142 (1986).
5. G.G. Luther, A.C. Newell, and J.V. Moloney, Physica D, 74, 59 (1994).