Fávero, L. P. L., P. Belfiore, M. A. dos Santos, and R. F. Souza. “Overdisp: A Stata (and Mata) Package for Direct Detection of Overdispersion in Poisson and Negative Binomial Regression Models”. Statistics, Optimization & Information Computing, Vol. 8, no. 3, June 2020, pp. 773-89, doi:10.19139/soic-2310-5070-557.