To cite package ‘bit64’ in publications use:

  Chirico M, Oehlschlägel J (2024). _bit64: A S3 Class for Vectors of
  64bit Integers_. R package version 4.5.99,
  <https://github.com/r-lib/bit64>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {bit64: A S3 Class for Vectors of 64bit Integers},
    author = {Michael Chirico and Jens Oehlschlägel},
    year = {2024},
    note = {R package version 4.5.99},
    url = {https://github.com/r-lib/bit64},
  }