1. 1) C. E. PEARSON : J. Inst. Met., 54 (1934), p. 111
2. 2) E. E. UUDERWOOD : J. Met., 14 (1962), p. 914
3. 3) C. HAMMOND : Superplastic Forming of Structural Alloys, ed. by N. E. PATON and C. H. HAMILTON (1982), p. 131 [AIME, New York]
4. 9) T. G. LANGDON : Metall. Trans. A, 13 (1982), p. 689
5. 13) H. W. HAYDEN, R. C. GIBSON, H. F. MERRICK and J. BROPHY : Trans. Am. Soc. Met., 60 (1967), p. 3