1. T. D. Lee, Particle Physics and Introduction to Field Theory (Harwood Acad., Chur, 1981).
2. L. B. Okun, Leptons and Quarks (North-Holland, Amsterdam, 1982).
3. E. D. Commins and P. H. Bucksbaum, Weak Interactions of Leptons and Quarks (Cambridge Univ. Press, Cambridge, 1983).
4. S. D. Bass, Eur. Phys. J. A 5, 17 (1999).
5. S. Capstick and N. Isgur, Phys. Rev. D 34, 2809 (1986).