To cite package ‘regions’ in publications use:

  Antal D (2021). _regions: Processing Regional Statistics_. R package
  version 0.1.8, <https://github.com/ropengov/regions>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {regions: Processing Regional Statistics},
    author = {Daniel Antal},
    year = {2021},
    note = {R package version 0.1.8},
    url = {https://github.com/ropengov/regions},
  }