In this paper, we obtain a new generalization of the negative binomial distribution (NBD) by
mixing the mean of the Poisson distribution with a generalized gamma distribution proposed by
Armero and Bayarri (Technical Report No. 93-50, Department of Statistics, Purdue University,
West Layette, IN) and Agarwal and Kalla (Comm. Statist. Theory. Methods 25(1) (1996) 201).
The resulting distribution has been