A. K. Bakhtin and A. L. Targonskii, “Generalized (n, d)-ray systems of points and inequalities for nonoverlapping domains and open sets”, Ukr. Mat. Zhurn., vol. 63, no. 7, pp. 867–879, Jul. 2011, Accessed: Apr. 07, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/2771