To cite package ‘IndexNumberTools’ in publications use:

  Serrano M (2025). _IndexNumberTools: Working with Index Numbers_. R
  package version 1.1,
  <https://CRAN.R-project.org/package=IndexNumberTools>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {IndexNumberTools: Working with Index Numbers},
    author = {Miguel Serrano},
    year = {2025},
    note = {R package version 1.1},
    url = {https://CRAN.R-project.org/package=IndexNumberTools},
  }