1. H. Sekizawa, T. Okada, S. Okamoto and F. Ambe, J. Physique C1-32 (1971) C1–326.
2. J.C. Love and F.E. Obenshain, AIP Conf. Proc. n°18, MMM Conf., Boston, 1973 (1974) p. 513.
3. J. Göring, W. Wurtinger and R. Link, J. Appl. Phys. 49 (1978) 269.
4. P. Gütlich, K.M. Hasselbach, H. Rummel and H. Spiering, J. Chem. Phys. 81 (1984) 1396.
5. J.J. Bara, Z.M. Stadnik, G. Czjzek, J. Fink, V. Oestreich and H. Schmidt, Hyp. Int. Proc. XVII Winter School, Bielsko-Biata, Poland, 1979, ed. R. Kulessa and K. Krolas (Cracow, 1979) p. 93.