DE BOECK, P.; PARTCHEV, I. IRTrees: Tree-Based Item Response Models of the GLMM Family. Journal of Statistical Software, Code Snippets, [S. l.], v. 48, n. 1, p. 1–28, 2012. DOI: 10.18637/jss.v048.c01. Disponível em: https://www.jstatsoft.org/index.php/jss/article/view/v048c01. Acesso em: 28 nov. 2021.