1. Feinberg, E. L. and Pomeranchuk, I.Suppl. Nuovo Cimento, 1955,36, 1089.
2. Good, M. L. and Walker, W. D.Phy. Rev., 1960,120, 1854;Ibid., 1960,120, 1857.
3. ----- .. “International Conference on High-Energy Phenomena,”CERN Report, 61–22, p. 263.
4. Drell, S. D...Rev. Mod. Physics, 1961,33, 458.
5. Mathews, P. T. and Salam, A.Nuovo Cimento, 1961,21, 126.