ZIVOT, E. W. State Space Modeling Using SsfPack in S+FinMetrics 3.0. Journal of Statistical Software, [S. l.], v. 41, n. 5, p. 1–27, 2011. DOI: 10.18637/jss.v041.i05. Disponível em: https://www.jstatsoft.org/index.php/jss/article/view/v041i05. Acesso em: 2 may. 2024.