Ardia D, Boudt K, Catania L. Generalized Autoregressive Score Models in R: The GAS Package. J. Stat. Soft. [Internet]. 2019 Jan. 29 [cited 2024 Apr. 26];88(6):1-28. Available from: https://www.jstatsoft.org/index.php/jss/article/view/v088i06