1. F. Jeglitsch, Proceedings of the International Symposium Niobium 2001, Niobium 2001 Ltd., Bridgeville, 2002.
2. D. S. Ma, J. H. Liu, Z. Z. Chen, A. J. Kang, H. X. Chi, Iron and Steel 43 (2008) No. 9, 67–70.
3. H. X. Chi, D. S. Ma, L. Z. Wu, Z. P. Zhang, Q. L. Yong, J. Iron Steel Res. Int. 17 (2010) No. 6, 43–46.
4. K. Kou, J. Iron Steel Inst. 173 (1953) 363–375.
5. K. Kou, J. Iron Steel Inst. 174 (1953) 223–228.