To cite perccalc in publications use:

Cimentada, (2019). perccalc: An R package for estimating percentiles from categorical variables. Journal of Open Source Software, 4(44), 1796, https://doi.org/10.21105/joss.01796

Corresponding BibTeX entry:

  @Article{,
    doi = {10.21105/joss.01796},
    url = {https://doi.org/10.21105/joss.01796},
    year = {2019},
    publisher = {The Open Journal},
    volume = {4},
    number = {44},
    pages = {1796},
    author = {Jorge Cimentada},
    title = {perccalc: An R package for estimating percentiles from
      categorical variables},
    journal = {Journal of Open Source Software},
  }