To cite package ‘birthdayproblem’ in publications use:

Höhle M (2017). birthdayproblem: Functionality for handling the birthday problem with unequal probabilities. R package version 0.0.0.9000, https://github.com/mhoehle/birthdayproblem.

Corresponding BibTeX entry:

  @Manual{,
    title = {birthdayproblem: Functionality for handling the birthday
      problem with unequal probabilities},
    author = {Michael Höhle},
    year = {2017},
    note = {R package version 0.0.0.9000},
    url = {https://github.com/mhoehle/birthdayproblem},
  }