V. F. Malik and I. V. Samoilenko, “Convergence of a semi-Markov process and an accompanying”, Ukr. Mat. Zhurn., vol. 62, no. 5, pp. 674–681, May 2010, Accessed: Dec. 05, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/2897