1. 1) L. -P. Lefebvre, et al.: Advances in Powder Metallurgy & Particulate Materials, (1997) 1-17.
2. 2) Kaneko and Homma: Magnetic Materials, 116 (1991).
3. 3) Iida: Sintered Mechanical Components Design Handbook, (1967).
4. 4) M. Konuma: Magnetic Materials.