ZEILEIS, A. Econometric Computing with HC and HAC Covariance Matrix Estimators. Journal of Statistical Software, [S. l.], v. 11, n. 10, p. 1–17, 2004. DOI: 10.18637/jss.v011.i10. Disponível em: https://www.jstatsoft.org/index.php/jss/article/view/v011i10. Acesso em: 21 may. 2022.