To cite package ‘era’ in publications use:

  Roe J (2024). _era: Year-Based Time Scales_. R package version 0.5.0,
  <https://CRAN.R-project.org/package=era>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {era: Year-Based Time Scales},
    author = {Joe Roe},
    year = {2024},
    note = {R package version 0.5.0},
    url = {https://CRAN.R-project.org/package=era},
  }