PIRAS, G. sphet: Spatial Models with Heteroskedastic Innovations in R. Journal of Statistical Software, [S. l.], v. 35, n. 1, p. 1–21, 2010. DOI: 10.18637/jss.v035.i01. Disponível em: https://www.jstatsoft.org/index.php/jss/article/view/v035i01. Acesso em: 3 feb. 2023.