To cite package ‘undomanager’ in publications use:

  Attali D (2026). _undomanager: Manage the History of Any Object with
  Undo/Redo Operations_. R package version 0.1.0.9000,
  <https://github.com/daattali/undomanager>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {undomanager: Manage the History of Any Object with Undo/Redo Operations},
    author = {Dean Attali},
    year = {2026},
    note = {R package version 0.1.0.9000},
    url = {https://github.com/daattali/undomanager},
  }