1. Nonlinear Formulation and Efficiency Enhancement of Free-Electron Lasers
2. N. M. Kroll, P. L. Morton, and M. N. Rosenbluth, in The Physics of Quantum Electronics: Free-Electron Generators of Coherent Radiation, edited by S. F. Jacobs, H. S. Pilloff, M. Sargent, M. O. Scully, and R. Spitzer (Addison-Wesley, Reading, MA, 1980), Vol. 7, p. 89.
3. D. Prosnitz, A. Szöke, and V. K. Neil, in The Physics of Quantum Electronics: Free-Electron Generators of Coherent Radiation, edited by S. F. Jacobs, H. S. Pilloff, M. Sargent, M. O. Scully, and R. Spitzer (Addison-Wesley, Reading, MA, 1980), Vol. 7, p. 175.
4. S. A. Mani, in The Physics of Quantum Electronics: Free-Electron Generators of Coherent Radiation, edited by S. F. Jacobs, H. S. Pilloff, M. Sargent, M. O. Scully, and R. Spitzer, (Addison-Wesley, Reading, MA, 1980), Vol. 7, p. 589.
5. Nonlinear analysis of efficiency enhancement in free-electron-laser amplifiers