HAMILTON, N. E.; FERRY, M. ggtern: Ternary Diagrams Using ggplot2. Journal of Statistical Software, Code Snippets, [S. l.], v. 87, n. 3, p. 1–17, 2018. DOI: 10.18637/jss.v087.c03. Disponível em: https://www.jstatsoft.org/index.php/jss/article/view/v087c03. Acesso em: 23 may. 2022.