To cite couplr in publications use:

  Colling G (2026). _couplr: Optimal Pairing and Matching via Linear
  Assignment_. doi:10.32614/CRAN.package.couplr
  <https://doi.org/10.32614/CRAN.package.couplr>. R package version
  1.8.1, <https://CRAN.R-project.org/package=couplr>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {couplr: Optimal Pairing and Matching via Linear Assignment},
    author = {Gilles Colling},
    year = {2026},
    note = {R package version 1.8.1},
    url = {https://CRAN.R-project.org/package=couplr},
    doi = {10.32614/CRAN.package.couplr},
  }