Proudnikov, l. M. (2007) “Construction of a stabilizing control and solution to a problem about the center and the focus for differential systems with a polynomial part on the right side”, CUBO, A Mathematical Journal, 9(3), pp. 13–28. Available at: https://cubo.ufro.cl/index.php/cubo/article/view/1584 (Accessed: 12 October 2025).