1. Alperin H A (1962), J Phys Soc, Japan, Supl B III 17, 12.
2. Bonnet M, Delapalme A, Tcheou F and Fuess H (1974), Proc ICM (Moscow, 1973 ) IV, 251.
3. Bonnet M, Delapalme A, Becker P and Fuess H (1978), J Mag and Mag Materials, 7, 23.
4. Brown R D and Burton P G (1970), Theoret Chim Acta, 18, 309.
5. Byrom E, Freeman A J and Ellis D E (1975), AIP Conf Proc (1974), 210.