To cite 'ph2hetero' in publications use:

Patrick Sfumato, Thomas Filleron and Bastien Cabarrou. (2018). ph2hetero: Stratified Adaptive Designs for Two-Stage Phase II Studies. R package version 1.0.2, https://CRAN.R-project.org/package=ph2hetero.

Corresponding BibTeX entry:

  @Manual{,
    title = {ph2hetero: Stratified Adaptive Designs for Two-Stage Phase
      II Studies},
    author = {Patrick Sfumato and Thomas Filleron and Bastien
      Cabarrou},
    year = {2018},
    url = {https://CRAN.R-project.org/package=ph2hetero},
    note = {R package version 1.0.2},
  }