1. See any text-book on the subject, for example, P. D. B. Collins and E. J. Squires, Regge poles in particle physics, Springer Tracts in Modern Physics Vol 45 (Springer Verlag, 1968)
2. V. Barger and D. Cline, Phenomenological theories of high energy scattering (W. A. Benjamin, New York, 1968)
3. N. Bali et al, Phys. Rev. 161, l450 (1967)
4. J. S. Ball and F Zachariasen, Phys. Rev. 179, 346 (1969)
5. A. E. A. Warburton, Nuovo Cim. 32, 122 (1964)