1. J. M. Jauch:Helv. Phys. Acta,31, 127 (1958).
2. See for instanceF. Riesz andB. Sz.-Nagy:Functional Analysis, esp. p. 384.
3. For the proof of these relations, see ref. (1)
4. N. Wiener:The Fourier Integral, (Cambridge, 1933).
5. J. M. Cook:Journ. Math. and Phys.,26, 82 (1957).