Ferkova, Z., and V. Kindl. “Influence of Skewed Squirrel Cage Rotor With Intermediate Ring on Magnetic Field of Air Gap in Induction Machine”. Elektronika Ir Elektrotechnika, vol. 23, no. 1, Feb. 2017, pp. 26-30, doi:10.5755/j01.eie.23.1.17580.