THOMAS, Laine; REYES, Eric M. Tutorial: Survival Estimation for Cox Regression Models with Time-Varying Coefficients Using SAS and R. Journal of Statistical Software, Code Snippets, [S. l.], v. 61, n. 1, p. 1–23, 2014. DOI: 10.18637/jss.v061.c01. Disponível em: https://www.jstatsoft.org/index.php/jss/article/view/v061c01. Acesso em: 25 mar. 2025.