1. Schwinger, J.: Phys. Rev. 75, 1912 (1949).
2. For example, Jackson, J. D.: Classical Electrodynamics. Chap. 14. New York: John Wiley and Sons 1962. There exists a new book by leaders in quantum calculations of synchrotron radiation; Sokolov, A. A., and J. M. Ternov: Synchrotron Radiation. English translation from the original Russian. Berlin: Akademie-Verlag 1968.
3. Feynman, R. P., R. B. Leighton and M. Sands: Feynman Lectures on Physics. Vol. 1. Chap. 34. Reading: Addison-Wesley 1965.
4. Ginzburg, V. L., and S. I. Syrovatskii: Ann. Rev. Astron. Astrophys. 3, 297 (1965).
5. Gardner, F. F., and J. B. Whiteoak: Ann. Rev. Astron. Astrophys. 4, 245 (1966).