1. T. P. Das, Physica Scripta11, 121 (1975) and references therein.
2. See for example the recent papers on nuclear quadrupole interactions edited by E. Karlsson and R. Wappling, ?International Conferences on Hyperfine Interactions by Nuclear Radiations and Decay, Invited Papers?, Physica Scripta (Sweden) Vol. 11 (1975) and also P. Heubes et al. Int. Conf. on Hyperfine Interactions, Uppsala (June 1974) contributed papers, p. 208.
3. R. S. Raghavan, E. N. Kaufmann and P. Raghavan, Phys. Rev. Lett.34, 1280 (1975).
4. D. Quitman, K. Nishiyama and D. Riegel, 18th Ampere Congress, Nottingham, (1974).
5. P. Jena, Phys. Rev. Lett.36, 418 (1976).