Hatzikonstantinou, P.; Moyssides, P. G. (1990). "Explanation of the ball bearing motor and exact solutions of the related Maxwell equations". Journal of Physics A: Mathematical and General. 23 (14): 3183. Bibcode:1990JPhA...23.3183H. doi:10.1088/0305-4470/23/14/017.
Hatzikonstantinou, P.; Moyssides, P. G. (1990). "Explanation of the ball bearing motor and exact solutions of the related Maxwell equations". Journal of Physics A: Mathematical and General. 23 (14): 3183. Bibcode:1990JPhA...23.3183H. doi:10.1088/0305-4470/23/14/017.