@misc{Harrell Jr.2017,
author = {Harrell Jr., F.  and Dupont, C. },
title= {Hmisc: Harrell miscellaneous},
year = {2017},
URL = {https://CRAN.R-project.org/package=Hmisc},
publisher = {FP2020},
address = {Washington, D.C.},
}