To cite package ‘CMIP5files’ in publications use:

  Sumner M (2024). _CMIP5files: What the Package Does (one line, title
  case)_. R package version 0.0.0.9000,
  <https://github.com/hypertidy/cmip5files>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {CMIP5files: What the Package Does (one line, title case)},
    author = {Michael D. Sumner},
    year = {2024},
    note = {R package version 0.0.0.9000},
    url = {https://github.com/hypertidy/cmip5files},
  }