To cite package ‘rFocal’ in publications use:

  Witthoft C (2025). _rFocal: Run 'FOCAL' Language Source Code_. R
  package version 1.0, <https://CRAN.R-project.org/package=rFocal>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {rFocal: Run 'FOCAL' Language Source Code},
    author = {Carl Witthoft},
    year = {2025},
    note = {R package version 1.0},
    url = {https://CRAN.R-project.org/package=rFocal},
  }