BALAN, T. A.; PUTTER, H. frailtyEM: An R Package for Estimating Semiparametric Shared Frailty Models. Journal of Statistical Software, [S. l.], v. 90, n. 7, p. 1–29, 2019. DOI: 10.18637/jss.v090.i07. Disponível em: https://www.jstatsoft.org/index.php/jss/article/view/v090i07. Acesso em: 2 may. 2024.