To cite package ‘a5R’ in publications use:

  Graham H (2026). _a5R: 'A5' Discrete Global Grid System_. R package
  version 0.4.0.9000, <https://github.com/belian-earth/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 0.4.0.9000},
    url = {https://github.com/belian-earth/a5r},
  }