UNWIN, Antony. Aabel 1.5.7. Journal of Statistical Software, [S. l.], v. 11, n. 1, p. 1–3, 2004. DOI: 10.18637/jss.v011.s01. Disponível em: https://www.jstatsoft.org/index.php/jss/article/view/v011s01. Acesso em: 6 apr. 2025.