To cite couplr in publications use:

  Colling G (2026). _couplr: Optimal Pairing and Matching via Linear
  Assignment_. R package version 1.4.0,
  <https://github.com/gcol33/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 1.4.0},
    url = {https://github.com/gcol33/couplr},
  }