To cite package ‘gamtree’ in publications use:

  Fokkema M (2025). _gamtree: GAM-based Recursive Partitioning_. R
  package version 0.0.3, <https://github.com/marjoleinf/gamtree>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {gamtree: GAM-based Recursive Partitioning},
    author = {Marjolein Fokkema},
    year = {2025},
    note = {R package version 0.0.3},
    url = {https://github.com/marjoleinf/gamtree},
  }