1. For more detail, see e.g. C.S. Wu and S.A. Moszkowski,Beta Decay (Wiley, New York, 1966)
2. M. Morita,Beta Decay and Muon Capture (Benjamin, Mass., 1973).
3. A.I. Boothroyd, J. Markey and P. Vogen, preprint.
4. E.g.,C. Rubbia, Asia Pacific Phys. Conf., Singapore (1983).
5. S. Weinberg, Phys. Rev. 112(1958)1375.