1. Cullen, J.R.: J. Appl. Phys. 52 (1981) 2038.
2. Koon, N.C., Williams, C.M.: J. Appl. Phys. 57 (1985) 3227.
3. Shimotomai, M., Komatsu, S., Doyama, M.: Proc. Int. Conf. Appl. Mössbauer Effect, Jaipur 1981, New Delhi: Indian Acad. Sci. Publ. 1982, p. 586.
4. Shimotomai, M., Fujisawa, H., Doyama, M.: J. Jpn. Inst. Metals 48 (1984) 233.
5. Atzmony, U., Dariel, M.P., Bauminger, E.R., Lebenbaum, D., Nowik, I., Ofer, S.: Phys. Rev. B 7 (1973) 4220.