To cite package ‘maddison’ in publications use:

Persson E (2025). maddison: Maddison Project Database. R package version 0.2, https://github.com/expersso/maddison.

Corresponding BibTeX entry:

  @Manual{,
    title = {maddison: Maddison Project Database},
    author = {Eric Persson},
    year = {2025},
    note = {R package version 0.2},
    url = {https://github.com/expersso/maddison},
  }