1. C. Castagnoli, C. Franzinetti andA. Manfredini:The Avogadro Conference on Fundamental Constants, Turin, September 1956, Italy (in press on theSuppl. of theNuovo Cimento).
2. T. D. Lee andC. N. Yang:Phys. Rev.,104, 254 (1956).
3. C. S. Wu, E. Ambler, R. H. Hayward, D. D. Oppes andR. P. Hudson, in press.
4. R. L. Garwin, L. M. Lederman andM. Weinrich, in press.