1. N.P. Goss, U.S. Patent No. 1965559
2. For example, M.F. Littmann, U.S. Patent No. 2599340; V.W. Carpenter and J.M. Jackson, U.S. Patent No. 2287467; V.W. Carpenter, S.A. Bell, and J.E. Heck, U.S. Patent No. 2385332
3. T. Sakai, inTrafotech-94, 4th Int. Conf. IEEMA, 1994, p 27
4. For example, S. Taguchi, A. Sakakura, and H. Takashima, U.S. Patent No. 3287183; S. Taguchi, A. Sakakura, T. Wada, K. Ueno, T. Yamamoto, and N. Urushiyama, U.S. Patent No. 3636579
5. N. Takahashi, Y. Ushigami, M. Yabumoto, Y. Suga, H. Kobayashi, T. Nakayama, and T. Nozawa, Production of Very Low Core Loss Grain Oriented Silicon Steel,IEEE Trans., MAG-22, 1986, p 490