To cite package ‘quantreg’ in publications use:

  Koenker R (2024). _quantreg: Quantile Regression_. R package version
  5.99, <https://CRAN.R-project.org/package=quantreg>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {quantreg: Quantile Regression},
    author = {Roger Koenker},
    year = {2024},
    note = {R package version 5.99},
    url = {https://CRAN.R-project.org/package=quantreg},
  }