PELAGATTI, M. M. State Space Methods in Ox/SsfPack. Journal of Statistical Software, [S. l.], v. 41, n. 3, p. 1–25, 2011. DOI: 10.18637/jss.v041.i03. Disponível em: https://www.jstatsoft.org/index.php/jss/article/view/v041i03. Acesso em: 17 oct. 2021.