LIAO, X.; MEYER, M. C. cgam: An R Package for the Constrained Generalized Additive Model. Journal of Statistical Software, [S. l.], v. 89, n. 5, p. 1–24, 2019. DOI: 10.18637/jss.v089.i05. Disponível em: https://www.jstatsoft.org/index.php/jss/article/view/v089i05. Acesso em: 23 may. 2022.