Loc Hung, Tran, Phan Kien, and Nguyen Tan Nhut. “Asymptotic Behaviors With Convergence Rates of Distributions of Negative-Binomial Sums”. Science and Technology Development Journal 22, no. 4 (January 28, 2020): 415-421. Accessed July 22, 2024. https://stdj.scienceandtechnology.com.vn/index.php/stdj/article/view/1689.