Gorst-Rasmussen, Anders, and Thomas H. Scheike. “Coordinate Descent Methods for the Penalized Semiparametric Additive Hazards Model”. Journal of Statistical Software 47, no. 9 (April 25, 2012): 1–17. Accessed December 4, 2021. https://www.jstatsoft.org/index.php/jss/article/view/v047i09.