OKHRIN, O.; RISTIG, A. Hierarchical Archimedean Copulae: The HAC Package. Journal of Statistical Software, [S. l.], v. 58, n. 4, p. 1–20, 2014. DOI: 10.18637/jss.v058.i04. Disponível em: https://www.jstatsoft.org/index.php/jss/article/view/v058i04. Acesso em: 3 jul. 2022.