To cite lpdensity in publications use:

  Cattaneo MD, Jansson M, Ma X (2022). “lpdensity: Local Polynomial
  Density Estimation and Inference.” _Journal of Statistical Software_,
  *101*(2), 1-25. doi:10.18637/jss.v101.i02
  <https://doi.org/10.18637/jss.v101.i02>.

A BibTeX entry for LaTeX users is

  @Article{,
    title = {{lpdensity}: Local Polynomial Density Estimation and Inference},
    author = {Matias D. Cattaneo and Michael Jansson and Xinwei Ma},
    journal = {Journal of Statistical Software},
    year = {2022},
    volume = {101},
    number = {2},
    pages = {1--25},
    doi = {10.18637/jss.v101.i02},
  }