To cite package ‘ssmodels’ in publications use:

  de Souza Bastos F, Barreto de Souza W (2026). _ssmodels: Sample
  Selection Models_. R package version 2.0.1,
  <https://github.com/fsbmat-ufv/ssmodels>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {ssmodels: Sample Selection Models},
    author = {Fernando {de Souza Bastos} and Wagner {Barreto de Souza}},
    year = {2026},
    note = {R package version 2.0.1},
    url = {https://github.com/fsbmat-ufv/ssmodels},
  }
