1. For a review of optical pumping:J. Brossel: inQuantum Optics and Electronics, edited byC. De Witt andA. Blandin (New York, N. Y., 1965);C. Cohen-Tannoudji andA. Kastler: inProgress in Optics, Vol.5, edited byE. Wolf (Amsterdam, 1966);W. Happer:Rev. Mod. Phys.,44, 169 (1972);
2. L. C. Balling: inAdvances in Quantum Electronics, Vol.3, edited byD. W. Goodwin (London, 1975).
3. C. Cohen-Tannoudji: inAtomic Physics, vol.4 (New York, N. Y., and London, 1975), p. 589;M. Ducloy:Phys. Rev. A,8, 1844 (1973);9, 1319 (1974).
4. F.i., seeH. Kopfermann:Nuclear Moments (New York, N. Y., 1958).
5. J. M. Winter:Ann. de Phys.,4, 745 (1959).