Fay, Michael P., and Pamela A. Shaw. “Exact and Asymptotic Weighted Logrank Tests for Interval Censored Data: The Interval R Package”. Journal of Statistical Software 36, no. 2 (August 5, 2010): 1–34. Accessed April 26, 2024. https://www.jstatsoft.org/index.php/jss/article/view/v036i02.