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2. C. G. Goetzel: Metals and Alloys (1937) 8, pp. 231, 245.
3. D. McLean and L. Northcott: Journal Inst. Metals (1946) 72, p. 583.
4. L. E. Samuels: Journal Inst. Metals (1949) 76, p. 91.
5. D. McLean: Journal Inst. Metals (1947) 73, p. 791.