To cite package ‘rfsrs’ in publications use:

  Longros C (2026). _rfsrs: R Bindings for FSRS Spaced Repetition
  Algorithm_. R package version 0.3.2,
  <https://github.com/open-spaced-repetition/r-fsrs>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {rfsrs: R Bindings for FSRS Spaced Repetition Algorithm},
    author = {Christos Longros},
    year = {2026},
    note = {R package version 0.3.2},
    url = {https://github.com/open-spaced-repetition/r-fsrs},
  }