To cite package ‘BOP2FE’ in publications use:

  Yimer B, Xu X, Hashimoto A, Homma G, Takeda K (2025). _BOP2FE:
  Bayesian Optimal Phase II Design with Futility and Efficacy Stopping
  Boundaries_. R package version 1.0.3,
  <https://github.com/belayb/bop2fe>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {BOP2FE: Bayesian Optimal Phase II Design with Futility and Efficacy
Stopping Boundaries},
    author = {Belay Birlie Yimer and Xinling Xu and Atsuki Hashimoto and Gosuke Homma and Kentaro Takeda},
    year = {2025},
    note = {R package version 1.0.3},
    url = {https://github.com/belayb/bop2fe},
  }