To cite package ‘trtf’ in publications use:

  Hothorn T (2023). _trtf: Transformation Trees and Forests_. R package
  version 0.4-2, <https://r-forge.r-project.org/projects/ctm>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {trtf: Transformation Trees and Forests},
    author = {Torsten Hothorn},
    year = {2023},
    note = {R package version 0.4-2},
    url = {https://r-forge.r-project.org/projects/ctm},
  }