A. N. . Sharkovsky, “Continuous mapping on a set of limiting points of an iterational sequence ”, Ukr. Mat. Zhurn., vol. 18, no. 5, pp. 127–130, Aug. 1966, Accessed: Dec. 06, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/8451