1. P. B. Anderson,Planseeber. Pulvermet. 15 (1967) 180.
2. H. Suzuki andK. Hayashi,ibid 23 (1975) 24.
3. E. Lardner andD. J. Bettle,Metals Mater. 7 (1973) 540.
4. O. R�diger andH. E. Exner,Powder Met. Int. 8 (1976) 7.
5. R. W. Davidge andA. G. Evans,Mater. Sci. Eng. 6 (1970) 281.