1. L. Akesson,Dissertation, Royal Inst. Tech. Stockholm, Sweden (1982).
2. V. Chabretou, O. Lavergne, S. Lay, L. Pontonnier, C.H. Allibert,Proc. PM 98, Vol. 4, p. 146, E. P. M. A., Granada, Spain (1998).
3. J. Gurland,Trans. AIME, Feb., 285 (1954).
4. M. Coster, J.L. Chermant, A. Deschanvres,Mémoires Scinetifiques Rev. Metallurg., LXIX 6, 465 (1972).
5. J.-L. Chermant, M. Coster, A. Deschanvres, A. Jost,J. of the Less-Common Metals 52, 177 (1977).