Ali, S. .; Ikram, J. .; Devereux, C. P. .; Bukhari, S. S. H. .; Khan, S. A. .; Khan, N. .; Ro, J.-S. . Reduction of Cogging Torque in AFPM Machine Using Elliptical-Trapezoidal-Shaped Permanent Magnet. ACES Journal 2021, 36, 1090-1098.