Sestelo, Marta, Nora M. Villanueva, Luis Meira-Machado, and Javier Roca-Pardiñas. “Npregfast: An R Package for Nonparametric Estimation and Inference in Life Sciences”. Journal of Statistical Software 82, no. 12 (December 6, 2017): 1–27. Accessed January 29, 2022. https://www.jstatsoft.org/index.php/jss/article/view/v082i12.