To cite package ‘a5R’ in publications use:

  Graham H (2026). _a5R: 'A5' Discrete Global Grid System_. R package
  version 0.5.0, <https://CRAN.R-project.org/package=a5R>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {a5R: 'A5' Discrete Global Grid System},
    author = {Hugh Graham},
    year = {2026},
    note = {R package version 0.5.0},
    url = {https://CRAN.R-project.org/package=a5R},
  }