Putri, D.M., Maiyastri, M. and Devianto, D. 2018. The Definite Positive Property of Characteristic Function from Compound Geometric Distribution as The Sum of Gamma Distribution. Science and Technology Indonesia. 3, 1 (Jan. 2018), 49–52. DOI:https://doi.org/10.26554/sti.2018.3.1.49-52.