KNOBLAUCH, K.; MALONEY, L. T. MLDS: Maximum Likelihood Difference Scaling in R. Journal of Statistical Software, [S. l.], v. 25, n. 2, p. 1–26, 2008. DOI: 10.18637/jss.v025.i02. Disponível em: https://www.jstatsoft.org/index.php/jss/article/view/v025i02. Acesso em: 4 dec. 2022.