1. 1) F. A. Badia: Trans. AFS, 79 (1971), 347.
2. 2) F. A. Badia, D. F. MacDonald and J. R. Pearson: Trans., 79 (1971), 265.
3. 3) F. A. Badia and P. K. Rohtagi: Trans. AFS, 77 (1969), 402.
4. 4) S. Watanabe: The 9th Symposium on Cast Composites and Their Manufacturing Techniques, The Japan Foundrymen’s Soc., Tokyo, (1981), p. 1.
5. 5) C. D. Herald and D. M. Schruggs: United States Patent No. 3468658, Sept., (1969).