Shakil, M., Dr. Mohammad Ahsanullah and Kibria, D.B.M.G.K. 2021. Characterizations of Some Probability Distributions with Completely Monotonic Density Functions . Pakistan Journal of Statistics and Operation Research. 17, 1 (Mar. 2021), 51-64. DOI:https://doi.org/10.18187/pjsor.v17i1.3491.