1. C. Yongjia: Powder Metall. Technol., 2001, vol. 19 (1), pp. 45–48
2. F.H. Froes: Mater. Technol., 2000, vol. 15 (4), pp. 295–99
3. F.H. Froes, and R.M. German: Met. Powder Rep., 2000, vol. 6, pp. 12–21
4. K. Ameyama, Y. Kaneko, H. Iwasaki, and M. Tokizane: J. Soc. Mater. Sci. (Jpn.), 1990, vol. 39 (437), pp. 120–25
5. C. Qiang, C. Yixiang, and Y. Yulai: J. Guangdong Non-Ferrous Met., 1999, vol. 9 (2), pp. 131–35