HEIBERGER, R.; ROBBINS, N. Design of Diverging Stacked Bar Charts for Likert Scales and Other Applications. Journal of Statistical Software, [S. l.], v. 57, n. 5, p. 1–32, 2014. DOI: 10.18637/jss.v057.i05. Disponível em: https://www.jstatsoft.org/index.php/jss/article/view/v057i05. Acesso em: 26 may. 2022.