Бояр-Созонович, С., В. Беликов, В. Саввушкина, and М. Эль-Амин. “Investigation of Axial Forces of a Contactless Self-Excited Asynchronous Generator With Axial Movement of a Rotor.”. Electrotechnic and Computer Systems, no. 19(19), Feb. 2019, pp. 149-52, https://eltecs.op.edu.ua/index.php/journal/article/view/433.