H. W. Lee, S. Y. Cho, J. N. Bae, B. O. Son, K. J. Park, J. Lee, Oct 2009, Yoke Shape
Design of Claw-Poles Stepping Motor Using Modified Magnetic Equivalent Circuit Method
Including Magnetic Saturation Effect and Leakage Flux, KIEE Transaction, Vol. 58,
No. 10, pp. 1942-1946