To cite package ‘portion’ in publications use:

  Oelschläger L (2026). _portion: Extracting a Data Portion_. R package
  version 0.1.3, <https://CRAN.R-project.org/package=portion>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {portion: Extracting a Data Portion},
    author = {Lennart Oelschläger},
    year = {2026},
    note = {R package version 0.1.3},
    url = {https://CRAN.R-project.org/package=portion},
  }