FIRTH, D. Bradley-Terry Models in R. Journal of Statistical Software, [S. l.], v. 12, n. 1, p. 1–12, 2005. DOI: 10.18637/jss.v012.i01. Disponível em: https://www.jstatsoft.org/index.php/jss/article/view/v012i01. Acesso em: 30 nov. 2021.