1. See for example: J. Needham, Science and Civilization in China, vol. 4, Cambridge University Press, New York, 1962.
2. G. Herzberg, Atomic Spectra and Atomic Structure, Dover Reprint, New York, 1944;
3. A. I. Akhiezer and V. B. Berestetskii, Quantum electrodynamics (translated by Oak Ridge Technical Information Service, ORNL, Tennessee, USA, 1957);
4. S. D. Drell, Ann. Phys. 4 (1958) 75.
5. S. J. Brodsky and S. C. C. Ting, Phys. Rev. 145 (1966) 1018.