To cite package ‘factorEx’ in publications use:

  Egami N, de la Cuesta B, Imai K (2025). _factorEx: Design and
  Analysis for Factorial Experiments_. R package version 1.1.0,
  <https://github.com/naoki-egami/factorex>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {factorEx: Design and Analysis for Factorial Experiments},
    author = {Naoki Egami and Brandon {de la Cuesta} and Kosuke Imai},
    year = {2025},
    note = {R package version 1.1.0},
    url = {https://github.com/naoki-egami/factorex},
  }