Маковкін, О., М. Диха, and В. Дитинюк. “About Determination of Contact Parameters by Dynamic Co-Operation of Sphere and Plane by a Power Method”. Problems of Tribology, Vol. 78, no. 4, Feb. 2016, pp. 17-22, https://tribology.khnu.km.ua/index.php/ProbTrib/article/view/480.