Cattaneo, Matias D., Michael Jansson, and Xinwei Ma. “Lpdensity: Local Polynomial Density Estimation and Inference”. Journal of Statistical Software 101, no. 2 (January 31, 2022): 1–25. Accessed November 21, 2024. https://www.jstatsoft.org/index.php/jss/article/view/v101i02.