To cite package ‘callr’ in publications use:

  Csárdi G, Chang W (2024). _callr: Call R from R_. R package version
  3.7.6.9000, , <https://github.com/r-lib/callr>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {callr: Call R from R},
    author = {Gábor Csárdi and Winston Chang},
    year = {2024},
    note = {R package version 3.7.6.9000, },
    url = {https://github.com/r-lib/callr},
  }