To cite package ‘tirt’ in publications use:

  Xiong J (2026). _tirt: Testlet Item Response Theory_. R package
  version 0.3.1, <https://CRAN.R-project.org/package=tirt>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {tirt: Testlet Item Response Theory},
    author = {Jiawei Xiong},
    year = {2026},
    note = {R package version 0.3.1},
    url = {https://CRAN.R-project.org/package=tirt},
  }