To cite package ‘plgraphics’ in publications use:

  Stahel W (2025). _plgraphics: User Oriented Plotting Functions_. R
  package version 1.4,
  <https://r-forge.r-project.org/projects/regdevelop>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {plgraphics: User Oriented Plotting Functions},
    author = {Werner A. Stahel},
    year = {2025},
    note = {R package version 1.4},
    url = {https://r-forge.r-project.org/projects/regdevelop},
  }