To cite package ‘OptOTrials’ in publications use:

  Park Y, Wang Y, Xu Z (2025). _OptOTrials: Optimal Two-Stage Designs
  for Ordered Categorical Outcomes_. R package version 1.0.2,
  <https://CRAN.R-project.org/package=OptOTrials>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {OptOTrials: Optimal Two-Stage Designs for Ordered Categorical Outcomes},
    author = {Yeonhee Park and Yudi Wang and Zhanpeng Xu},
    year = {2025},
    note = {R package version 1.0.2},
    url = {https://CRAN.R-project.org/package=OptOTrials},
  }