Копач, Михайло Іванович, et al. “SYSTEMS DIFFERENTIAL INEQUALITIES WITH ONE-SIDE LIPSCHITZ RIGHT PARTS”. PRECARPATHIAN BULLETIN OF THE SHEVCHENKO SCIENTIFIC SOCIETY. Number, no. 1(9), Mar. 2019, pp. 26-33, https://pvntsh.nung.edu.ua/index.php/number/article/view/282.