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2. 2) F. B. PICKERING and T. GLADMAN : Iron and Steel Inst. Spec. Rep. No. 81 (1963), p. 10
3. 3) W. JOLLEY : JISI, 206 (1968), p. 170
4. 4) M. J. ROBERTS : Metall. Trans., 1 (1970), p. 3287
5. 5) A. HOLDEN, J. D. BOLTEN and E. R. PETTY : JISI, 209 (1971), p. 721