1. T. T. Chou andC. N. Yang:Phys. Rev.,170, 1591 (1968);H. Cheng andT. T. Wu:Phys. Rev.,182, 1852 (1969);S. Y. Lo:Nucl. Phys. B,19, 286 (1970);S. Y. Lo, Li Yang-Guo, Liu andXian-Hui:Physica Energie Fortis et Physica Nucleairis,5, 653 (1981), China.
2. T. T. Chou andC. N. Yang:Phys. Rev. D,22, 610 (1980);Phys. Rev. Lett.,46, 764 (1981);S. C. Chan, S. Y. Lo, H. B. Low andK. K. Phua:Phys. Rev. D,17, 802 (1978);C. H. Lai, S. Y. Lo andK. K. Phua: NUS-HEP-8002 (1982), preprint.
3. S. Y. Lo:Lett. Nuovo Cimento,2, 124 (1969).
4. UA2Collaboration: CERN-EP/82-62 (1982) for $$\bar pp \to \pi ^0 X$$ at √s = 540 GeV;P. Capiluppi G. Giacomelli, A. M. Rossi, G. Vannini, A. Bertin, A. Bussière andR. J. Ellia:Nucl. Phys. B,79, 189 (1974) for pp → π+X at √s = 53 GeV;W. Akerlof, D. G. Crabb, J. L. Day, N. P. Johnson, P. Kabbaci, A. D. Krisch, M. T. Lin, A. L. Read, K. W. Edwards, J. G. Asbury, G. J. Marmer andL. G. Ratner:Phys. Rev. D,3, 645 (1971) for pp → π+ + X atP lab=12.5 GeV or √s = 4.66 GeV.
5. UA4Collaboration: CERN-EP/82-76 (1982); CERN-EP/82-111 (1982).