To cite package ‘graticule’ in publications use:

  Sumner M (2024). _graticule: Meridional and Parallel Lines for Maps_.
  R package version 0.3.0, , <https://github.com/hypertidy/graticule>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {graticule: Meridional and Parallel Lines for Maps},
    author = {Michael D. Sumner},
    year = {2024},
    note = {R package version 0.3.0, 
},
    url = {https://github.com/hypertidy/graticule},
  }