To cite package ‘first’ in publications use:

Huang C, Joseph V (2025). first: Factor Importance Ranking and Selection using Total Indices. R package version 2.1, https://CRAN.R-project.org/package=first.

Corresponding BibTeX entry:

  @Manual{,
    title = {first: Factor Importance Ranking and Selection using Total
      Indices},
    author = {Chaofan Huang and V. Roshan Joseph},
    year = {2025},
    note = {R package version 2.1},
    url = {https://CRAN.R-project.org/package=first},
  }