V. V. Goryainov, “Estimates of the extinction probability of the Galton-Watson process”, Ukr. Mat. Zhurn., vol. 47, no. 2, pp. 290–291, Feb. 1995, Accessed: Dec. 06, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/5414