To cite the 'sirt' package in publications use:

  Robitzsch, A. (2024). sirt: Supplementary Item Response Theory
  Models. R package version 4.1-15.
  https://CRAN.R-project.org/package=sirt

A BibTeX entry for LaTeX users is

  @Manual{sirt_4.1-15,
    title = {sirt: Supplementary Item Response Theory Models},
    author = {Alexander Robitzsch},
    year = {2024},
    note = {R package version 4.1-15},
    url = {https://CRAN.R-project.org/package=sirt},
  }