To cite package ‘Directional’ in publications use:

  Tsagris M, Athineou G, Adam C, Yu Z (2024). _Directional: A
  Collection of Functions for Directional Data Analysis_. R package
  version 6.8, <https://CRAN.R-project.org/package=Directional>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {Directional: A Collection of Functions for Directional Data Analysis},
    author = {Michail Tsagris and Giorgos Athineou and Christos Adam and Zehao Yu},
    year = {2024},
    note = {R package version 6.8},
    url = {https://CRAN.R-project.org/package=Directional},
  }