1. M. M. Islam:Lett. Nuovo Cimento,4, 447 (1970);Phys. Lett.,31 B, 313 (1970);Phys. Today, No. 5,27 (1972).
2. T. T. Chou andC. N. Yang:Phys. Rev.,170, 1591 (1968);Phys. Rev. Lett,20, 1213 (1968).
3. M. D. Warty:Nucl. Phys.,51 B, 553 (1973).
4. M. M. Islam: University of Colorado Summer School,Lectures in Particle Physics (1969), p. 127.
5. M. Abramowitz andI. Stegun:Handbook of Mathematical Functions (New York, 1965), p. 375.