To cite package ‘pdfsigner’ in publications use:

  Leite A, Vasconcelos H, Bezerra D (2026). _pdfsigner: Digitally Sign
  and Verify PDF Documents_. R package version 0.2.2,
  <https://CRAN.R-project.org/package=pdfsigner>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {pdfsigner: Digitally Sign and Verify PDF Documents},
    author = {Andre Leite and Hugo Vasconcelos and Diogo Bezerra},
    year = {2026},
    note = {R package version 0.2.2},
    url = {https://CRAN.R-project.org/package=pdfsigner},
  }