HØJSGAARD, Søren; HALEKOH, Ulrich; YAN, Jun. The R Package geepack for Generalized Estimating Equations. Journal of Statistical Software, [S. l.], v. 15, n. 2, p. 1–11, 2005. DOI: 10.18637/jss.v015.i02. Disponível em: https://www.jstatsoft.org/index.php/jss/article/view/v015i02. Acesso em: 6 apr. 2025.