To cite package ‘GBOP2’ in publications use:

  Fang X, Lei W, Zhou S, Chen P, Chen R, Wong W, Lee J (2025). _GBOP2:
  Generalized Bayesian Optimal Phase II Design (G-BOP2)_. R package
  version 0.1.4, <https://CRAN.R-project.org/package=GBOP2>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {GBOP2: Generalized Bayesian Optimal Phase II Design (G-BOP2)},
    author = {Xinying Fang and Wanni Lei and Shouhao Zhou and Ping-Yang Chen and Ray-Bing Chen and Weng Kee Wong and J. Jack Lee},
    year = {2025},
    note = {R package version 0.1.4},
    url = {https://CRAN.R-project.org/package=GBOP2},
  }