1. 3) F. W. IRWIN: J. Metals, 22 (1970), p.30
2. 6) A. L. GENTILE,: J. Amer. Ceram. Soc., 46 (1963), p.44
3. 7) R. WOLDSETH: X-ray Energy Spectrometry, Kevex Corp. Burlingame, Cal, 1973
4. 10) R. KIESSLING: Non-metallic inclusions in steel, Part III, The Iron and Steel Institute, London SW 1, 1968
5. 13) L. LUYCKX,: J. Metals, 26 (1974), 6, p.35