1. W. C. Roberts-Austen,Proc. Roy. Soc. (London), 23, p 481–495 (1875).
2. C. T. Heycock and F. H. Neville,Phil. Trans. Roy. Soc. (London), A189, p 32–36, 57–58 (1897).
3. K. Friedrich and A. Leroux,Metallurgie, 4, p 297–299 (1907).
4. T. Hirose,Mem. Imp. Mint Osaka, 1, p 1–74 (1927);Proc. World Eng. Congr. Tokyo (1929), 36, p 37 (1931).
5. W. Broniewski and S. Kostacz,C. R. Acad. Sci. Paris, 194, p 973–975 (1932).