To cite package ‘ctqr’ in publications use:

  Frumento P (2025). _ctqr: Censored and Truncated Quantile
  Regression_. R package version 2.2,
  <https://CRAN.R-project.org/package=ctqr>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {ctqr: Censored and Truncated Quantile Regression},
    author = {Paolo Frumento},
    year = {2025},
    note = {R package version 2.2},
    url = {https://CRAN.R-project.org/package=ctqr},
  }