Yamnenko, Rostyslav, and Volodymyr Levchenko. “Estimation of Ruin Probability for Random Sum of Negative Binomially Distributed Number of Sub-Gaussian Claims”. Bulletin of Taras Shevchenko National University of Kyiv. Physics and Mathematics, vol. 80, no. 1, July 2025, pp. 40-46, https://doi.org/10.17721/1812-5409.2025/1.5.