To cite package ‘longitudinalData’ in publications use:

  Genolini C (2024). _longitudinalData: Longitudinal Data_. R package
  version 2.4.7, <https://CRAN.R-project.org/package=longitudinalData>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {longitudinalData: Longitudinal Data},
    author = {Christophe Genolini},
    year = {2024},
    note = {R package version 2.4.7},
    url = {https://CRAN.R-project.org/package=longitudinalData},
  }