[1]Akhmanov S A, Sukhorukov A P, Khoklov R V. Self-focusing and self-trapping of intense light beams in a nonlinear medium. Soviet Phys Uspekhi, 1968,10:609-636
[2]Zauderer E. Partial differential equations of applied mathematics. New York: Wiley-Interscience, 1989
[3]Ng K C. Self-focusing and self-trapping of spherical beams in a nonlinear medium. Tamkang Journal of Mathematics, 1994,25(2)