Loc Hung, Tran, Phan Kien, and Nguyen Tan Nhut. 2020. “Asymptotic Behaviors With Convergence Rates of Distributions of Negative-Binomial Sums”. Science and Technology Development Journal 22 (4), 415-21. https://doi.org/https://doi.org/10.32508/stdj.v22i4.1689.