Гончар, В., and П. Каплун. “Studying the Properties of the Nitrided Layer Steel ШХ 15 and Its Wear in Abrasive Environments”. Problems of Tribology, vol. 67, no. 1, May 2014, pp. 36-42, https://tribology.khnu.km.ua/index.php/ProbTrib/article/view/83.