Bugenis, S. J., J. Vanagas, and S. Gečys. “Optimal Phase Number of Induction Motor With the Integrated Frequency Converter”. Elektronika Ir Elektrotechnika, vol. 88, no. 8, Oct. 2008, pp. 67-70, https://eejournal.ktu.lt/index.php/elt/article/view/11344.