1. Review of Particle Physics: Phys. Rev. D54, 561 (1996)
2. M. Giannini: Rep. Prog. Phys. 54, 453 (1991), and references therein
3. W. Chiang and F. Tabakin: Phys. Rev. C55, 2054 (1997)
4. SAID data base, quoted in R. A. Arndt et al.: Phys. Rev. C52, 2120 (1995)
5. P.S.L. Booth et al.: Nucl. Phys. B71, 211 (1974), and references therein