1. R. J. Prem andP. H. Steinberg:Phys. Rev.,136, B 1803 (1964);b) N. Crayton, D. H. Davis, R. Levi Setti, M. Raymund, O. Skjeggestad, G. Tomasini, R. G. Ammar, L. Choy, W. Dunn, M. Holland, J. H. Roberts andE. N. Shipley:Proceedings of the 1962 International Conference on High-Energy Physics at CERN (1962), p. 460;c) R. G. Ammar, W. Dunn andP. Aolland:Phys. Lett.,3, 340 (1963);d) Y. W. Kang, N. Kwak, J. Schneps andP. A. Smith:Phys. Rev. Lett.,10, 302 (1963).
2. M. M. Block, C. Meltzer, S. Ratti, L. Grimellini, T. Kikuchi L. Lendinara andL. Monari:Proceedings of the 1962 International Conference on High-Energy Physics at CERN (1962), p. 458;b) M. M. Block, R. Gessaroli, J. Kopelman, S. Ratti, M. Schneeberger, L. Grimellini, T. Kikuchi, L. Lendinara, L. Monari, W. Becker andE. Harth:Proceedings of the International Conference on Hyperfragments CERN, 64-1 (1964), p. 63.
3. R. H. Dalitz andG. Rajsekharan:Phys. Lett.,1, 58 (1962).
4. R. H. Dalitz:Proceedings of International Conference on Hyperfragments CERN, 64-1 (1964), p. 147.
5. B. D. Jones, B. Sanjeevaiah, J. Zakrzewski, N. Csejthey-Barth, J. B. Lagnaux, J. Sacton, M. J. Beniston, E. H. S. Burhop andD. H. Davis:Phys. Rev.,127, 236 (1962). (For subsequent references seee.g. Y. Prakash andS. P. Goel:Nuovo Cimento,51 A, 340 (1967).